Question, Don.
In the COACC, under Fixed-Wing Aircraft Design on page 32, the weights for Airframe per Metric Ton of Final Aircraft Weight are as follows.
TL 4 (assume should be 5) Simple 0.01 or 10 Kilograms.
TL 6 Fast Subsonic 0.05 or 50 Kilograms
TL 6 Transonic 0.10 or 100 Kilograms
TL 6 Supersonic 0.20 or 200 Kilograms
TK 6 Hypersonic 0.30 or 300 Kilograms
Are those the correct figures?
The reason that I ask is that the following is taken from US Navy Bureau of Aeronautics Airplane Characteristic Charts.
F4F-4 had an empty weight of 5895 pounds, and a loaded weight of 8762 pounds. Applying the 0.01 figure would give the F4F-F an airframe weight of 87.62 pounds.
The PB4Y-2 Privateer patrol bomber, a single tail version of the B-24 Liberator, shows an empty weight of 37,464 pounds and a max take-off weight of 64,000 pounds. Applying the 0.01 figure would give the Privateer an airframe weight of 640 pounds.
The F9F-2 Panther jet fighter shows an empty weight of 9303 pounds and a max take-off weight, land air field only, of 19,494 pounds. Applying the 0.05 factor for fast transonic aircraft, gives the Panther an airframe weight of 974.7 pounds.
I have the data for US Air Force fighters and bomber for the Post-War period up to 1973, with in some case the cost for each major aircraft component. The weights get a bit closer with the later aircraft with the 0.30 figure, but the early ones are maybe just a bit "strange".
If you want, I could get out my books on civil aircraft to for comparison, but based on the R4D-5 Skytrain, the Navy's version of the DC-3, those are going to be as bad. The Skytrain shows an empty weight of 17,057 pounds and a max take-off weight of 29,000. Applying the 0.01 figure, as the DC-3 flew for the first time in 1935, would give the airframe weight as 290 pounds.
Edit Note: I have information on 1920s airships and also early helicopters if you want it. Those airframe weights for early ones are strange as well. Then there is also the case of massive differences in performance between aircraft using the same power plant. I assume that you do not want information on those.