I'm very flattered! It's genuinely good to be getting back to Ars Magica.
My understanding of the laboratory rules is that you can enchant an item to improve your lab. If it duplicates the effect of a virtue, whee--don't worry too much about levels, just get the bonuses. If not, every 10 levels can give you +1 in a specialization like Creo, Experimentation, or Spells; every 20 levels can give a +1 in a characteristic like Safety, General Quality, etc.
Here are some of the items in more detail. Quite a few of these are from memory--one 5th ed saga is ongoing, with relatively new gamers, so I'm slightly forgiving on formulae. The other was 8 years ago, and I'm going largely from memory. I ask your patience if my numbers are a bit off as I'm re-creating them now.
Mirror of Opposition: This laboratory item is enchanted to take a contrarion position when engaged in debate. Its purpose is both to provide insights and ideas the user might not have thought of at the current moment, and also to provide cautionary advice against too much enthusiasm. This item gives a +1 bonus to a specialization in Experimentation, and a +1 to Safety.
ReMe 10, +2 Voice, +1 Conc, +10 Unlimited Uses per day, +5 item maintains concentration.
This is a Rego Mentem effect, as it temporarily pushes the user's mind to a contrary position--it's an opinion he could hold, it is simply not one he holds at this moment in time. It is still his mind coming up with the idea. The mirror appearing to speak is a cosmetic effect and requires no requisite.
Healing Blankey: This item's main claim to fame is its amusing name--yes, we call it "blankey". It's a CrCo effect with concentration that the item maintains. It gives a bonus to recovery rolls, of as high a total as possible to still be enchanted as a lesser device. (My Verditius specialized in Corpus and had a very high magic theory, so I think I managed a +9). It does not give bonuses to lab, but instead it can be used by covenfolk, indirectly contributing to the magi's leadership score.
Horseshoe of Healing: Similar to the blanket above, this is a CrAn item with a target of Structure. A roll on the experimentation table had an amusing result: Any animal injured and benefitting from the recovery roll gives a different animal's vocalization while it is recovering. For example, we have a horse with a broken leg that quacks until its leg is healed. As above, this is more to help the covenfolk than give a specific bonus.
Eldritch Chamber: This glass-caged device is designed to inflict Warping. When an item (or creature) is placed into it and the device is engaged, the device inflicts two warping points upon the subject. This gives a +2 bonus in a specialization in Vim. CrVi 10, +1 touch, +5 levels 24 uses per day, final level 20. We had to keep yelling at each other not to call it 'The Microwave.'
A simple MuIm spell to change a fire's hue over time. My merinita can spont it. It's designed for the grogs to enjoy their environment a bit more. Again, the only bonus is an indirect one to our Leadership score. Only after I did this spell, did I realize my character had essentially invented the screen saver.
A CrAq spell to hasten a lake's 'recovery' rolls. +1 Touch, +3 Moon, +1 size, and as high a recovery bonus as the roll gave me. Under most circumstances, I would assume this would need a Momentary Ritual instead, but I was able to justify this as giving the water a bonus to its 'recovery' roll. It had been a healing spring that improved the humors twenty years ago, giving a +1 to Living Conditions. However, in the interim, a boglin (GotF) had infested it, turning it into a fetid swamp. The Living conditions was instead a -1. Once the boglin was slain, the pollution source was removed. In my judgment, the lake would slowly start recovering and improve the Living Conditions to a 0 and then a +1. My spont'ed spell simply improved the recovery 'roll,' similar to a CrCo or CrAq non-ritual healing spell.
Armchair of Pleasant Rest: CrMe, Base 4, +1 touch, +3 Room. I'm going on memory on this one, so I could be off on both the base and whether or not this should be Rego. Apologies. regardless, this enchants a room so that anyone sleeping in it has restful, healthy sleep. The duration is only Momentary, so this sleep is not supernaturally maintained. Instead, it just 'nudges' them towards a good night. I could probably justify this being a +1 to Health, but instead decided it would simply be a gift to the covenfolk, a behind-the-scenes improvement to our Leadersihp score, as several other items were. (I wasn't overly sure of the ruling, so I figured I should be stricter with the requirements if it was going to give a numeric bonus).
I also stole Conscentina's ex Bonisagus's pretzel maker from Magi of Hermes. I want one of those in real life! My Merinita (minor focus in Ice) may make something similar. You guessed it, Mythic Europe's first smoothie and snow-cone maker!
Those are some of the more fun ones I can remember. If you have feedback on more appropriate levels, do please let me know. I'm going on an 8-year-old memory. (Even at the time, I remember thinking "Well, by golly, this needs to be level 30 for a +1 to Characteristics and +1 to a specialization--how do I get it there?")
...oh dear god, I think I actually seriously convinced myself to have my Merinita invent that snow-cone maker.