I casually collect antique furniture and always look for worn- in original condition pieces. There is an historic "feel" to an original piece that restored variants don't seem to carry.
I'm sort of in the same boat. The only thing that sways me in the other direction is playability.
We've all stepped up to a tired EM with uneven playfield and it's just not always that much fun. When I restored my Centigrade 37 and filled in all the cupped inserts and airbrushed all the vibrant colours back it just felt sooooo sweet! The game plays like butter and the historian in me always loses when I stop to think that "this is how it must have played on day 1".
Then there is this example.
I don't really care too much how this 1937 Bally Booster plays. It's more of a fixture or piece of furniture in my office.
It gets turned on and fed pennies maybe once a month. I am never touching this machine aside from the initial cleaning and waxing I gave it. I have to look at things on a project by project basis.
Spot Bowler is supposed to be a pretty good player.
If you look at the layout, those pins (lamp covers) are the main objective. You can spot them via the pops and the outlanes, but you are really shooting for the centre STRIKE target to get them all. The more strikes, the higher the score. If you are just off centre and get the red rollover, you will "knock down" a little over half of the pins. If you get the outside yellow rollover, just the two outer pins on that side get taken down.... just like real bowling. So, this is a game where I don't want funny ball movement from cupped inserts.
Anyway, it's still along way off. Too many other projects. I will have time to think on this one for a while.