But neither season has been executed, yet. He is lining out seasonal activities, with the goal of financing lab enhancment (construction?).
This may be a problem if this is total lab construction.
Going back to the OP, this isn't counterfeiting, per se. The silver will still have the intrinsic value. Counterfeiting typically meant constructing the coin of base metals and gilding it witht he precious ones.
The goal is financing lab enhancement. Based on the responses I've seen so far, I'm currently leaning toward inventing a ritual spell to create the lump o' silver, then inventing a ReTe spell that includes some flexibility (i.e. not just one type of coin) and an extra magnitude to enhance the Finesse roll. I think the ReTe spell will look like this...
ReTe 20
The Minter's Run
Turns up to (1/10 cubic foot of precious metal) or 65.5 lbs of silver (or about twice that of gold) into an appropriate number of a coins. A Finesse roll is required to produce coins with a specific design (i.e. to duplicate actual coinage).
(Base 2, +1 Touch, +2 metal, +1 fine detail, +1 complexity (one lump into many coins), +1 Finesse bonus (+3))
...but I may have missed something. The character's lab ReTe lab score is currently 43, so both spells are within reach. Even if it needs another magnitude for complexity/detail/etc., he's only a few years from reaching a lab score of 50.
Good point, and it raises another question. Does the ReTe spell I described above need to specify precious metal? 
Just out of curiosity... what lab enhancements?
That opens a can of worms that I'm going to address in a diff thread... here: How flexible is a formulaic spell?
These 2 would work:
Add one or two Magnitudes and let that halve the Finesse roll EF instead of removing it.
If you´re creating and affecting actual precious metal, yes.
Never really liked that one, it SHOULD be Target Group at the very least. As written it breaks the rules AFAIK.
In the short term, Lesser Expansion and Specimens. Long term, I'm looking at several options (Gr Expansion, Lesser Horde, Superior Equipment) that will increase the upkeep. The covenant can afford increases to annual costs - it's the upfront cost I'm trying to cover.
For the specimens, I'd see if you can get your BSG going on a story where you go out and collect them. No muss, no fuss with funding.
Now the Lesser Expansion...how expensive do you think it should be. By my reckoning, adding Lesser Expansion only adds 10 build points which would cost 5 mythic pounds.
It's still counterfeiting if you simulate the mark of an existing mint on the coins you make. You can make your own "Order of Hermes" coins, perhaps with a bust of Bonisagus on them, but then you're operating a mint without royal permission. Authorized mints were good profit centers for kings and local authorities because they could charge "Seigniorage" on the coins they made. Essentially a silver penny would have slightly less silver content than would be expected by weight, with the difference covering the cost of the mint and profit for the authority. Rule hath its privileges.
Usually counterfeiting comes with the expectation of (near-)valueless coins. Here, the coins are not so much counterfeits as replicas, so, while technically illegal, even if someone notices (unlikely if done wisely) who's to care?
(As an aside - why bother with the coinage? A lump of pure silver should be tradeable at a reasonable rate to most any merchants or silversmiths. And on that subject, as has been pointed out in other threads, larger CrTe spells to create larger amounts of silver give a much better return on silver vs. vis spent.)
Doh... Had´nt seen that. Despite having read through that part of the errata even.
I like the idea, but I'd rather avoid using it because of the nature of our troupe. We have a fairly large group (seven players) and we don't have time to game very often. If I start asking for stories dedicated to my character, everyone else should be free to do the same and we just don't have time for that. It's hard enough addressing all the story flaws.
Correct. I'm not worried about covering the Lesser Expansion, or even Specimens, using the covenant's current resources. However, looking ahead to future enhancements, the up-front cost is going to increase significantly (per Covenants).
If you're going to be spending pounds near/above the high single-digit quantity, why do you feel that coins are necessary, rather than bullion silver?
Hadn't much thought about it, really. I guess it seemed like coins would be easier to spend/trade than bullion and less likely to draw undue attention. The covenant is on the Orkney Islands north of Scotland, which have minimal metal deposits, but is active in mundane trade (wool, fishing, whaling). The covenant having/spending a decent quantity of coinage could be easily explained (should it come up). Owning and trading significant amounts of bullion seems more noteworthy and suspicious, IMO.
The deciding factor is what the StoryGuide's opinion is, or the Troupe's, true.
But at 240 (silver) coins to the pound, bar silver is not an uncommon medium for large purchases (and it's trivial to mundanely melt a single lump of silver into bars, even easier with a bit of magic). More, if your mage is going to purchase lab items, they aren't going to be spending the money in the Orkneys (nor anywhere near, I'd imagine), so it's going to be harder to trace it back. On top of that consideration, if the Covenant goes thru a middleman or agent who travels to the source (quite possibly worth the travel expense, esp if your mage's will be part of a larger group purchase), then buying in a distant major city (like Venice, for instance) makes the expenditure of a few dozen pounds of equipment even less conspicuous and that much harder to trace.
Or, silversmiths in a big city may be willing to buy bulk silver, especially if the price is right. Add a disguise spell and the problem is even more remote.
Not that coins don't have their use, just saying that not having that second spell may not be a dealbreaker.