Yea that is a late R4001 "Rebel" this still had leftovers of them in 1976 (the $106 scribbled on the bottom of the sheet indcates what you it would cost an employee of muskin for one of the remaining 35 they had in stock in late 1976). The engine on it post dates the bike though by at least 15 years and is originally off a Snowblower, Still a really clean, well done build!
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