Dear Mode One:
The PIPE here again...
please do NOT forget to contact WW I AERO about your needed Alby D II info....
....and I've remembered a number of scratchbuilt WW I RC models being done in 1/5th scale by none other

than Tom Polapink !!!
Tom's favorite scale ratio size sure SEEMS to be 1/5th scale, as he's built a number of RC scale aircraft TO that scale.
I'd HAVE to agree with you that virtually nothing's available "so far" in the 1/5th scale size for accessories like dummy MGs, instruments, etc...
...and since Balsa USA seems to have already done up a number of different MGs in 1/6th, 1/4th and 1/3rd scales, perhaps they might be persuaded to make up at least their Vickers, Lewis and Spandau dummy MGs in that scale to start to help out the fans of 1/5th scale WW I aircraft.
There DOES seem to be a line of 1/5th scale dummy MG kits from Arizona Model Aircrafters, viewable online at
Armament Sets , Model Airplane Kits RC Arizona Model Airplanes Aircrafters , but with the "questions"

that company seems to have had in the past, with the level of pre-fabrication IN their kit's materials, versus the price paid (the 1/5th dummy MG kits all seem to be $45 in price) for their products, you MIGHT want to ask around for advice before ordering from AZM.
That's all I can offer for now...but Tom Polapink
IS a biig fan of 1/5th scale, so you MIGHT want to get in touch with him on the issue of 1/5 scale WW I detailing accessories...!
Yours Sincerely,
The PIPE!