Actually, BillRo, the stand in question is indeed from the Northrop Display Model Shop. We did use that style of base when I got there in 1984, especially and nearly exclusively for the 1/60th and 1/72nd scale YF-17s, early F/A-18s and F-5s. We were also using the black injected plastic bases for 1/40th scale F/A-18s, F-5s, T-38s and especially F-20s. In the late '80s and early 90s we went to a triangle wood base with curved upright similar to what Toys & Models went to (we think they copied us, btw, but who knows). We also did a broad wood base with straight back and sides and pointed front for the 1/72nd and 1/100th scale B-2s.
As far as farming out work, the 1/60th scale solid plastic models were produced outside and sent to the shop as blanks. We added some small details and then prepped, painted and finished the models. 1/40th scale T-38s and F-5As and Bs were also done outside, originally by Topping, as injected plastic half shells, but eventually Dick Guiselman got the molds back and we had the blanks done by other vendors. We then assembled the two fuselage halves, added various small parts, then prepped, painted and finished the models.
1/40th scale F-5Es and Fs were done in-house as primarily resin-cast fuselages with injected styrene wings and tails surfaces.
1/40th scale F-20s were injected plastic shell vendor blanks similar to the T-38s and F-5As and Bs.
1/200th scale B-2s were vendor finished solid models.
The mid-to-late 1990s saw us try different base styles. By the early 2000s we settled on a pentagon-shaped base for most of our in-house work, with a few odd-ball styles thrown in (including some vendor-made bases) due to time pressures, availability and/or compatibility with existing models in a particular display.
That time frame also saw a sharp decline in models solely produced in-house. We built the master models, but basically nearly all 1/72nd scale YF-23s and 1/48th scale F/A-18s were or are done outside. We now have the YF-23 mold in-house, so those are now internal models, but the demand is so small as the vendor models are so prolific on eBay. We used to finish the PacMin F/A-18C/D/E/F blanks, but now we've gone to getting finished E/F models and just re-painting the canopies with our sky/cloud signature style. Nearly all F-35s are from Toys & Models. We don't even bother with re-painting canopies on them. 1/72nd scale Global Hawks, 1/48th UCAS and 1/24th scale Fire Scout models are nearly all finished vendor models, too, although we do have the capability to do in-house as well. However, no one wants to pay the cost of in-house anymore, except for internal studies, one-offs or special trade-show models.
Oh, well. Change is eternal and Time marches on.