Patrick,
If you are using CT-18, be very very thorough about rinsing it off, and don't leave it too long.
It's
very corrosive to aluminium alloys, if left in contact over time. I've seen this in situations such as riveted sheet joints, or spoke nipple holes on wire wheels. These are 'crannies' that it will seep into, but can't be rinsed out of.
As far as the Masport goes, you now know to not let anything with a complete OHV Honda engine on it get away!

These are a commercial duty engine, and can be easily fitted to a lot of different chassis - Victa is the only exception.