Well its been about 10 years since I joined so I guess I should post something

In 1973 I had an atc70 (I still have it) later in the 70s I went to work at Murry Hertz Honda in Las Vegas Nv (car and Mc ) and when Murry sold the business in 77 or so we were going through a storage unit where he kept all the old stuff not needed in the parts dept and I found service bulletin #3 and the spark arrester kit that went with it. Apparently prior to frame number 1004075 the 1973 ATC 70s did not have a certified spark arrester ( I believe they just didn't have the approval of the paperwork from the Forrest service done in time of the first shipment of atc70s) and this was the fix to comply with the Forrest service requirements.

Any way I was just going through my stash of first gen atc70 stuff and came across this.
It also might be the first Honda part made in the US , it was made for honda by the Taylor Prod Divison a part of Tecumseh