Crosland 672 or Purflux LS489A according to the cross-refs. at <A target="_blank" HREF=http://www.filtrauto.com>Filtrauto</A>, who make both brands.
If you read some of the oil filter reviews on the web, by people who have the time and inclination to cut them up and compare the internals (!), you won't fit any other make to your beloved engine.
Crosland should be easy to get. For Purflux you may have to hunt around the shelves at you local Peugeot or Citroen dealer.
Good advice about filters is not to skimp. A friend recently had to rebuild his Petter after it seized due to lack of oil. Some oil filters have o-ring seals, others have a flappy bit of rubber skirt. If the latter, you won't notice failure until all the oil is in the biges and the warning light comes on. Or not, in his case. Even a genuine Yanmar filter is cheaper than a crankshaft re-grind, or a tow off the mud!
I don't suppose there's a generic 1GM10 engine diesel filter too, is there? I mean the one that's fitted actually where the fuel arrives, under the pump. Cost of these sort of parts from Yanmar is a bit rich. After the better part of £20 for the air filter and £7 for a little banjo bolt, I'm rather off enriching them any further.
halfords ought to be able to x ref. as in any other motor factor.
i always go to the "little guy" who is always cheaper than halfords & knows what an engine looks like, unlike the children in the halfords shpo