The CM450a which Honda produced for two years (82 & 83) is basically the same bike as the CM400A which was produced for 3 years (79, 80 & 81) except that Honda took the 400 motor and bored it to produce the 450. Basically all the CM400 variants (CM400A, CM400T, CM400C & CM400E) of the same time period and the CM450A have parts that can be interchanged to a major extent. If you search for parts utilizing all the variants, they are readily available on EBay. Because the CM models are not as popular as the early to mid 70's CB models, second hand parts don't tend to cost as much. As far as reliability, the bike is bullet proof. With the Hondamatic, the engine typically is less stressed. It's not the quickest bike, doesn't have a lot of power, but makes a great starter bike. I loved my CM400A for in town commuting. There are times that still I regret sellling mine.