Like all those years ago - very few hop ups made that much difference to be honest - the same is true today. The average modern (and driver back in the day especially) would be far better off spending their money on tires and consumables to get more practice. That alone will make them far more consistent and quicker on the track than any hop up!!

As far as the old day hop ups go back then - I could never afford them (even though I was "supported" by different companies at times), as my mum and dad went without to afford the hobby even at my reduced pricing! I used to take great pleasure in racing and being competitive with all the adults and "rich kids" with all the latest "go-fast" hop up and batteries etc.
There is no "performance hop up" like track time.
Then again - damn the hop ups look so so sweet.
Again - such a good selection of period hop ups. I particularly like how you have kept the original 6 gear transmission in there.........period correct.
Cheers
Darryn