engine bars for a CB250/400 Superdream...
how could i know if these would fit my 200?

Err... try fitting them?

its doubtful m8, engine bars are made for specific bikes-the 250/400 is the same frame,so the bars will fit both bikes but the 250 frame is a lot bigger than yours, as i said in an earlier post its going to be difficult to say the least to find stuff to fit your bike.
www.davidsilverspares.co.uk do stuff they specialise in hondas old & new, check them out-might be worth a try.
i know i keep saying this but you'd be better off selling the cb 200 as an original classic & buying something more modern to play/customise.

Yeah you're probably right DP.
I just saw these bars and thought "they're cheap, would be good if they worked"

TBH I haven't got the money to do my test at the moment nor to get my bike on the road and probably wont' have for months.
let alone buying any bits now