Welcome frownfork. Cant wait to see more of your build, its a real nice start. And you are right about everyone helping you out, i couldnt have done my builds without the help of members on here. If you can, post lots of pics, i do and wish more people would. It helps others out a lot. And helps with others advising you.
I know you said you were looking for Villiers midgets in a mower. Youre on the right track. Just noticed your in Australia which makes it easy. Ive been watching for a while now and noticed on Ebay you can buy a complete mower the same price or cheaper as most engines alone. And with the mower you get a kickstarter, cool fuel tank for future projects and other stuff: steel, sprockets, throttle lever and maybe you could even use the clutch (i dont know if thats possible). Search "reel" or "cylinder mowers" on Ebay and wait for a cheapie. I picked up one for $20 not long ago. Good luck man and dont hesitate to ask for help, i dunno much but willing to help where i can.