Hi Beatle and welcome to Outdoorking.
The first point I would make is that using a dozer blade with a rather high-geared machine controlled by a friction clutch would only work if the friction clutch was rather big, and the user's expectation both for dirt moved and for clutch life was rather low. The small wheels will also be a factor - you may find you do more digging with the back wheels than with the blade. Re-lining Greenfield clutches is a bit of a pain, since the whole clutch countershaft has to be removed, dismantled, and then shimmed up to give the correct clutch clutch clearance, before reassembly into the chassis. Not an awful job, but not one you'd want to do every six months either. So, before getting committed to the project I'd suggest you talk to someone who actually uses a blade with a Greenfield and get some feedback. Greenfield clutches are not unreasonably small for a mower, especially if it is expertly operated (i.e. you keep the engine speed set low when you are backing and filling to manoeuvre the beast) but bulldozer clutches they are not. More importantly, the Greenfield mowers are not geared for dirt-moving, they are geared for mowing.
So far as fitting the blade is concerned, I think the first point of contact should be the Greenfield factory service people. I'm told they are somewhat cooperative if you quote the model and serial numbers of the machine.
In case of desperation people here may be able to help with a cobbling project, but lots of pictures and dimensions would be required, and more model identification. I haven't been able to figure out the Greenfield model names at all, and judging by the comments from owners who come here, and the profusion of parts lists with overlapping names, I'm not the only one.
