According to the samba archives there were no montana red bus' after Aug 1970 so Chianti red would be a safe bet, unless it was a CKD from Oz or SA. Where is the bus from?
Evening Aspro
I think it's a UK bus but, I can't be absolutely certain due to the M - plate being disposed of by some other nice chap!
Do you happen to know of any other way of finding out? No history other than a couple of previous owners who didn't care? Something about a birth certificate?