If I went down to a smaller more minimal inboard that could be an affordable option. Say a 12 hp yanmar? The boat will be underpowered but I'm in no hurry.
From what I've seen to work on inboards one must crawl back into dark cramped areas in contortionist positions - it all looks quite gross. How much do you reckon some sort of workable small diesel could be had for? I really hate spending money on engines and investing energy and time into planet destroying monstrosities... I also am not sure I can lift inboards and will be doing all the work myself. The boat is currently in the water and aside from hauling it for survey I wasn't planning to keep it on the hard but rather to buy it and start sailing right away.
I read through the thread and have been contemplating what a monstrosity a transom mount might be - its ugly, it adds holes (leaks) where there needn't be any and it will only work in calm water and work poorly in that the boat will be very slow. I could probably do the outboard for some $1500 maybe less if I find a steal on the motor. I haven't figured out how to reinforce the transom. The good thing is the mount could be on a quick release bracket and the whole monstrosity taken off as soon as I get to sailing grounds. The prop and shaft can be removed for a faster hull - the space of the inboard converted to sail lockers etc and A couple hundred pounds less weight.
I suppose the advantage of doing an engine swap myself is I will learn all about my new boat. It seems the 3GMD is obsolete I will have to change to a different motor anyway and I lean toward smaller and simpler and most of all cheapest.