I will have to double check on the Panther APCR. I believe it was your buddy Miles Krogfus who claimed that the squeeze gun 75mm and Panther used the same bolt.
In any case, these are production numbers as far as stock on November 1942 for the Pak40. (thousands)
7,5 cm Sprgr Patr 34 (7,5 cm Pak 40): 533.1
7,5 cm Gr Patr 38 Hl (7,5 cm Pak 40): 917.6
7,5 cm Pzgr Patr 39 (7,5 cm Pak 40): 945.3
7,5 cm Pzgr Patr 40 (7,5 cm Pak 40): 1.7
7,5 cm K Gr rot Nb (7,5 cm Pak 40): 30.3
That is just for the Pak 40 antitank gun and any Marder types mounting that weapon. Clearly 7,5 cm Pzgr Patr 40 is a minority type. Supposedly in the field in January 1943.
Compare those numbers with the rare 7,5 cm Pak 41...
7,5 cm Sprgr Patr 41 (7,5 cm Pak 41): 25.2
7,5 cm Pzgr Patr 41 H K (7,5 cm Pak 41): 63.3
7,5 cm Pzgr Patr 41 St K (7,5 cm Pak 41): 0
The Panzer IVs and StuG...
7,5 cm Sprgr Patr 34 (7,5 cm Kw K 40 and Stu K 40): 498.4
7,5 cm Gr Patr 38 Hl (7,5 cm Kw K 40 and Stu K 40): 412.8
7,5 cm Pzgr Patr 39 (7,5 cm Kw K 40 and Stu K 40): 747.6
7,5 cm Pzgr Patr 40 (7,5 cm Kw K 40 and Stu K 40): 22.1
7,5 cm Gr Patr Nb (7,5 cm Kw K 40 and Stu K 40): 22.6
I would certainly assume that there were more Pak 40 around than there were panzer IV and StuG (L43 and L48) in November 1942. Yet, they seem to have less than a couple thousand rounds of APCR?
Check these numbers for the 7,62 cm Pak 36 and F K 39...
7,62 cm Sprgr Patr 39 (7,62 cm Pak 36 and F K 39): 1042.4
7,62 cm Pzgr Patr 39 rot (7,62 cm Pak 36 and F K 39): 476.5
7,62 cm Pzgr Patr 40 (7,62 cm Pak 36 and F K 39): 77.8
I suspect that Kursk and the rest of 1943 may have been the heyday for most German use of APCR. The Germans pulled the 7,5 cm Pak 41 out of service, and sometime in 1943 recalled all APCR ammunition. They also had the bolts that were not yet assembled into ammunition stocked as a reserve. The numbers of these made for the smaller calibers is remarkable.