Flintknapper
ArboristSite Operative
It's either a 6900, 7700 or 8500, Al. AFAIK there's no way of telling with the decal being in the condition it's in other than measuring the bore. Sorry. I don't have the bore measurements. Congrats on your find though.
Color scheme is correct for any of those saws.
I believe the 6900's had the model number stamped on the aluminum plate just above the serial number, don't know about the other two.
8500 would be sweeeeeet!