Smashemup,the silver Comstars came on some SOHC's and the early DOHC's. The black Comstars only came on DOHC's. I dont know if there were specific to F models or not. It does seem like that,though.
All of the silver Comstars came with those black plastic tabs. Some of them just fell off through the years. That threw me for a loop when I first started looking at them,too. My 76F (the burgundy bike in the pics) came with spoke wheels originally but the PO swapped the Comstars onto my bike. It was a rear disc brake bike originally also. Even with the spokes.
I know you aren't argueing. No worries! Ask away,I'll be glad to misinform you