So far, the following drawings of the Model 124/147/234/259 have surfaced:
'Lightning Bugs' contains a nice set of 1:56 scale drawing of the BQM-34A (Q-2) Model 124 target drone (page 10). These will be useful for comparison with the Model 147, which was based on the Model 124.
'Lightning Bugs' contains a front and upper view of the 147NA / AQM-34G, without a scale (pages 155 and 156).
The conference paper 'RPV sensor system interface' (see technical papers) includes a drawing of the Model 259 BGM-34C, but without dimensions. However, when scaled according to published data (length and span), it agrees very nicely with components of the (shorter) Italeri BQM-34. This drawing appears to be the best drawing of the AQM/BGM-34 family by far.
The Airmodel vacform comes with drawings, in a scale different than 1/72. The drawings are as wrong as the models. To be ignored completely.
An undetermined issue of the Czech magazine L+K shows drawings almost 100% identical to those supplied with the Airmodel kit. It is unknown who is the original source, Airmodel or L+K. The page is numbered 'L+K 78/554' suggesting a 1978 issue. But the lay-out and fonts used make it look like something more modern. Anyway, the drawings are useless, they are inaccurate to a high degree.
An AIAA paper on aerodynamic loads modeling (no. 74-346, see technical papers section) contains outline drawings of the AQM-34R. They are very basic, but an important first step if you want to model the 'biggest wing' Model 147.
A US Army site (see links below) has a recognition drawing of the BQM-34A. It is largely identical to that from 'Lightning Bugs', except for tailplane endplates (possibly ALE-40 chaff/flare dispensers), a set-back and larger intake that seems to be the current configuration, and the wing sweep is slightly larger than the 45 degrees that I believe is correct.