Are you a member of the Salonika Campaign Society? It may not be all that large in numbers but it is enthusiastic and Ruth and I thoroughly enjoy going to the AGM. We lay a wreath at the Cenotaph then have lunch, the AGM (which isn't drawn out) and then a talk about the Theatre. Last year's was
Up The Struma With The Gas-pipe Cavalry, about the Cyclists Battalion.
The map in the OH is rather small to be definitive. The SCS has brought out a disk of trench maps, which are 1:20000 and 1:50000 but they mostly cover the XII Corps front, unfortunately for you. Have you found the Austro-Hungarian ones yet? They'e not the best for accuracy - but they are free! They're
HERE.
Having got the advert for the SCS out of the way

I'd hardly call myself a guru on the area. I frequently get defeated by the place-names because of, as you say, the multiplicity of spellings for many and the subsequent hellenisation, so that Janes became Metalliko and Harmankoi (another place with umpteen spellings!) is Evosmos, for example. If you Google for Macedonian Village Names you'll find a non-exhaustive list that's quite helpful. Adrian Wright has helped me a lot with his local knowledge but I do know that he's been quite busy lately and hasn't been on the Forum much. I suggest you stick a list up in this area and see what we can do for you.
Oh, yes. Nearly forgot. Don't get too precious about finding the exact spot from the place-name. It's one thing if the Diary says "32 Kilo Seres Rd" but not if it says Orljak, Guvesne or Lahana. Diaries appear to use the nearest place, even if it's in ruins, as a tag. In some cases, AA sites are well over a kilometre from where you'd expect to find them and I don't doubt that similar short-cuts were taken by other units.
Keith