I have it now! Found it in town, finally. It's late here now, so I'll get to translating the rules and posting images tomorrow. First impressions are that it's more like Princess and Dragon rather than The Tower, in that it includes four distinct gameplay components; that the components should favour more tactical/cutthroat players; and that the Abbey of the title is probably the weakest of the four. As far as worries about the anticipated new rules for farmers are concerned, I think that the 'barn' feature will actually simplify farmer scoring - but probably only if you're using HiG rules. Basically, placing the barn on a farm means all farmers currently on it are scored immediately, and no further farmers can be placed on the farm. The barn trumps farmers, and I don't see how RGG can square that with 1st edition rules.
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I've just found a link to the RGG rules translation
here (thanks to
the BGG thread). The RGG solution to the 'barn' problem is: to use 3rd edition rules with the barn. I don't see any indication to say that all farming rules are now 3rd edition; which would indicate that either you stop using 1st edition rules altogether, or that you use both sets, 1st edition for normal farms, and 3rd edition for barn-occupied farms.
So, I'll go through the original and RGG's translation in more detail tomorrow, and see what I come up with.