Thanks for that.
I love these old aftermarket catalogues.
When I was a kid (and could ride reasonably fast) I would dream of being able to afford any mods.
Now I'm old and slow, I have a few "tricked up" bikes. (While I enjoy racing them, I'm embarrassed and depressed about MY performance.)
I note:
1. The bikes were so undeveloped that aftermarket improvements could mean massive gains.
2. "Adding boost ports, modifying Pistons and intake ports" were considered standard fare, and within the capabilities of most riders.
Many of today's riders struggle to wash a bike, let alone perform machining modifications. (Option 1 let dad wash it. Option 2 stand back and blast it with a pressure washer.)