Hey Gazza, I have restored one like this not long ago, plus I have 1 pulled apart at the moment. A mate has 4 wheels and a victa name plate front deck, and may consider a sale....at a price.
The 18'' has a round muffler but I am not sure if it is still on the market.
What do you mean by colour sceam, are you referring to the colour scheme? if so, I painted mine mostly green and detailed it in black, while the letters on the front deck I painted red.
If you can be more specific in what help you need with parts and information I will try to assist you.
RGDS Jacko