Thank you NormK, I appreciate the time spent responding. Merci beaucoup.
The 3 stud wheels don't seem to be a problem to get off under normal circumstances, however this scenario had me resort to the angle grinder to remove wheel. I now see that the axle flanges are different, with the donor model having the bolt and, I assume, a key holding the flange to the axle, but the recipient model having the flange welded on. This means I'll attempt to have three new bolts welded onto the back of the flange as it appears they were originally, although I'm not 100% certain of that. I've also located someone who will do the welding, and assures me 60 odd metres of extension cord shouldn't be a problem. Not having a cordless angle grinder, I did run the cords down to the shed to run my corded grinder with no problems. So hopefully a small portable welder won't have a problem.
I've attempted to attach photos, but they don't appear in the preview available so I'll post and hope they appear. If not, I'll try again.
So, to summarise for anyone needing some help, there appears to be at least two different flange arrangements (diff lock side) on Greenfields of similar sizes and with diff locks (are there Greenfields without?), although I'm not sure of the ages of each of these machines. One type has the flange welded, the other secured with bolt and key (I'm assuming). So no transplant of flanges possible in this instance. I think I've read about short and long axles- maybe the axle flange difference relates to this axle difference- I'm just guessing though.
