Vintage Horticultural and Garden Machinery Club

hello all this is my first post
I have always loved old machinery, I grew up in my dads carpentry workshop using his antique machinery and was especially fond of his planer thicknesser which was originally operated by a steam powered line shaft and over 100 years old (he would occasionally threaten to by a new one but thankfully never did) it was this that sparked my early interest and now I have the chance to start my first project

I have inherited a shay rotogardener 80, it belonged to my partners great grandfather
the plan is to get it working on our new/first allotment this year
It seems to be in good nick and not long out of use judging by the fuel I drained from it.
The inlet manifold had come apart were the flange is pressed onto the tube which is now welded solid.
There was no spark but after abit of fiddling with the ignition it is now good

I would really appreciate some help as I cannot find any manuals or information on the machine, if someone could point me in the right direction to find one that would be great, or if anyone could answer a few questions I would like to know
-what oils to use in gearbox and air filter
-if there is a better way to set up the ignition timing than just trial and error

many thanks in advance