I'm sure I've seen it somewhere but I can't find the reference.
I'm looking for any printed reference to Tribunal rulings on what type of items a Magus can sell to a mundane.
I seem to remember that different levels of society can be treated differently; say a single pawn of vis for the lowly and a rook of vis for the pope himself. That sort of thing.
Can anyone remember where these limits might be found?
Yes, and loosely quoting from memory, you can't sell to a mundane any enchanted device that works permanently, only charged items, and there is a threshold on the value of the item, which I don't remember now, Serf's Parma, sorry.
As far as I remember, it's a ruling valid for the Rome Tribunal only, I don't seem to remember it was adopted by the Great Tribunal in canon, even if it is a sensible guideline that the whole Order could perfectly adopt in your saga.
Or items with an expiration date. Also note that you must work through intermediaries to sell anything.
Commoners: at most 1 pawn, items affects only itself or the holder.
Minor noble, bishop, merchant prince: at most 2 pawns, items affects only itself or the holder.
High noble, archbishop: at most 3 pawns, item can affect a single remote person.
King, cardinal: at most 4 pawns, item can affect several remote persons.
Items that can harm large masses of people are restricted for sale to magi only.
Cause I've got this one in another town. It's not just a bridge, but a toll way. You can make a lot of money if you buy it. See I've got a lot of bridges and I just can't maintain them all. The point is I'll sell it to you for cheap....