While I agree there is a bit too much levity in some of these vintage racing classes, and especially what the "was a big name back in 19xx" are allowed to get away with.
I think certain concessions need to be made to certain parts on the big that don't necessarily make the bike go faster, but are needed to make a decent replica. Things like Fox air shocks, forx , simons forks etc are unobtanium for us mere mortals. only so many were made in the first place and you definitely don't see them popping uop on ebay all the time. Sure certain big names will build a bike and have all those trick parts on them, but they tend to be only passed about the 'in crowd' when they do come up for sale.
They should allow thing like mid 80s YZ for example 43mm forks or whatever the other big 3 makes have that fits easily. rear shocks should be free, I think the air shocks are actually worse than a normal shock because as they get hotter the spring rate increases. so a good dialed in set of ohlins could actually be better here. Things liike brakes should be whatever you can fit / adapt as if something makes a bike safer, it should not be a controlled item. I agree some of these bikes are looking silly with their way-higher-than-original suspension stance, and the worst offender I saw recently was a poweroll kitted 74 XL350 that looked like it was trying to immitate a CR 500..
But I digress,
more bums (including some of us LOL) on seats out there can only be good for the sport no matter whatg the bike looks like.
Some of these bikes for us are like living our dreams with the steads that our heroes rode back in the day, that we couldn't afford back then, and still really can't now lol
Take it easy all