I'll give it a try for you Ben. I used to do a LOT of plane spotting at Llanbedr while camping at the adjacent Shell Island. Lots of happy memories!
EDIT:
I just checked and it looks like there are some problems on my system using FSX + Accel and no scenery mods in that area (I do have the Snowdonia VFR Demo installed but that area stops just NE of Llanbedr).
Around the hangars and the taxiways I am getting a 'raise' of about 3 ft (1m) above stock ground level as can be seen in this screenie.....
Strangely I am getting a lowering on the runways....but only on one side! :doho: ...See this screenie....
Of course I had to use Rick's beta of the Hawk in the Valley skin to test it out ;-) . Unfortunately I am on a disability pension and cannot afford to buy the full version yet (sorry Rick :-( ).
Incidentally I see you are using ADE for the scenery mods. I have been using that for a while too (I am working on a RAF Lossiemouth update with Tony (Techy111)) and it is a great little tool.
Anyway, sorry for the bad news about Llanbedr and a stock FSX build.