Using ADE175, screwed save file

Using ADE175 i was in the middle of saving the file when a power outage occurred, screwing not only the .ad4 file but also the .ad4.bak file making them both unusable. I reloaded from the .bgl file but of course this does not load the _GP or _TER files. I tried importing them over the main .bgl file and despite no error message neither of them actually were imported.

Fortunately I had a backup of the _GP and _TER files and copied them into the relevant folder. This works fine but each time I edit the original airport file and compile it, they both disappear.

Is there any way I can recombine all three files?