The only "1050" and "1052" I can find are for LSI-BBTS-LF's. If these speakers are unitary construction (not split HF and LF) I don't believe we have a record.
A very few "Tremulant" Klipschorns were offered. I haven't counted them in the logbook which would be a significant "project". However, I believe less than 20 were built. The museum has one courtesy of eBay. The paddle was driven by a turntable motor mounted in the back of the HF module.
1E166 was the last recorded serial number, so 666 in total seems to be correct. At the beginning of the logbook it says: "Began giving serial numbers to assembled Shorthorns both decorated and utility. Started on 25 Jan 56 with ser. # 501". That COULD imply that un-serialized units exist.
Without actually measuring one I can't say with 100% certainty. However, the T2A drops the thru-put in 3 dB steps (-3, -6, -9, -12). Its very likely that PWK needed a further 3 dB drop (-12), resulting in the "A" suffix.
Checking with Gary Gillum, the resin included black pigment. Areas that were not glassed (LS and MWM interiors) got the standard black lacquer. In the case of the 260 horn, black gel coat was applied to the mold prior to layering with glass and black pigment.
1265 and 1266 are listed as slant monitors (angled cabinet) and were shipped 5/23/78 to Chujko Bros.
1267 and 1268 are listed as HIP's (ported rectangular cabinet) and were shipped the same day to Turntables Unlimited.
I couldn't tell you an exact color specification, however, I suspect it was the "same black" lacquer used for basically everything else.
Aluminum trim was purchased from Macklanburg-Duncan. They still offer some trim, but I'm not sure about the "odd angle" for the LS doghouse.
https://mdbuildingproducts.com
They are the "original" Cornwall II's. 159 and 160 shipped on 12 Nov. 1971, and 161 and 162 shipped 3 days later. No clue about destinations. What is exceedingly rare (and curious) is that 162 was signed by RLM. That is Bob Moers, President of K&A. He is at the left during construction of the Plexiglas K-horn, at roughly the same point in time.