It is a similar situation to the "restorer" that was sanding down Mata Hari Pinballs, repainting them, installing a repro playfield and then calling it "The best KISS Pinball ever".. That was easily debunked when an owner did a serial number check and it was a Mata Hari. Then later auctions has the serial numbers conveniently sanded during the repaint. Finally, later auctions had serial numbers highlighted, "pretending" that the seller was merely trying to illustrate the head and backbox serial numbers matched.
With WPC games, it is easy to scan a genuine MM serial number and then print it as many times as needed. I have personally seen a machine that was a Congo, but the conversion process left the original stickers in place.
The converted games I've seen always have the following ;
Poorly printed cabinet decals than peel back easily due to lack of preparation and poor quality print. I'd like to stress these were not "Next Gen", but reproduced decals. Having an original next to a conversion demonstrated the difference in colours and texture. Don't go too aggressive with Nifti !
Repro playfields with brand new game specific mechanisms etc - New Troll carriages, moats popper assy, moat subway ramp, castle parts.. Of course these can be excused as part of a "restoration", but most sellers won't go to this level and just use second hand parts - which they don't have because the game is a conversion..
Wiring harness - Playfield either new (which can be purchased) or "home made". Poor soldering to mechs etc.
Boards - The last conversion I saw simply had the ROMs replaced (AV and CPU boards). Look at the stickers on the ROMs. Conveniently ALL non factory white labels. Dead giveaway. You don't need to reprint the ROMs on a restored game, and MM does not have ROM revisions other than Profanity and one code update.. Changing the ROM labels for the sake of it is a really the domain of a restorer who just has to update and refresh everything.
Regarding the increased interest of the conversions by hobbyists / Collectors - I have no issue whatsoever with conversions. I've spoken to a few friends and they would attempt this, and I would be comfortable that they would be honest on resale. I'm sure most people won't mind if they know beforehand, and they can judge the workmanship of a hobbyist.
As far as I'm concerned, if a customer came to me with a Congo or NBA Fastbreak and requested I convert it, I would do it.
I think that if there was a "backyard" attempt at mass conversions, based on what I've seen, it would be an area which will have consequences for buyer and seller.
