I've noticed one more thing, while reading Polish article on German attack aircraft:
Spain OOB33:
378 He 51 Cadenas, 379 CASA C- 51 - bomb load 500kg is impossible for this plane (all useful load was 440 kg) - and the quoted article explicitly says, that He 51 were first used by Nationalists as pure strafers, then Legion Condor started to employ them with 6x10 kg bombs (the same load in
https://en.wikipedia.org/wiki/Heinkel_He_51) - from early 1937, I guess? (the Legion arrived in November).
From late 1937 there was produced attack variant He 51C-1 with 4x50 kg bombs, which appeared in Spain, but I don't know when.
BTW: I think that name CASA is not justified, since they weren't manufactured in Spain; neither Spanish Wikipedia uses it
https://es.wikipedia.org/wiki/Heinkel_He_51
Same for German OOB unit
340 He 51 - early one could use 6x10 kg bombs at best [now 2x50 kg]
Apparently the same for Bulgarian unit
157 He 51 Sokol - they were He 51B (Bulgarian book "Air Power of the Kingdom of Bulgaria" vol.3 indicates 2 MGs only anyway, so it isn't clear if they had bomb racks at all...)
Spain:
374 Ju 87B1 Stupido, 375 CASA C-87B - typical single bomb was 500 kg, 1000 kg could be carried with overload (
https://de.wikipedia.org/wiki/Junkers_Ju_87) - and I don't know if such heavy bombs wee used in Spain, anyway typical variant might be better.
BTW: it isn't clear, if they and 376 CASA C-87G were used in Spain after SCW at all - Legion Condor ones returned to Germany, and it is strange, that Spanish Wikipedia doesn't list Spain among users at all...
https://es.wikipedia.org/wiki/Junkers_Ju_87. Neither Wings Palette lists any Spanish color profiles apart from SCW
http://wp.scn.ru/en/ww2/b/29/67
370, 371 Breda Ba.65 - although Italian Wikipedia says "1000 kg (carico teorico)" (
https://it.wikipedia.org/wiki/Breda_Ba.65) but in fact according to articles they could take 4 x max 100kg in a bomb bay (though usually it was 4x50kg). Spanish Wikipedia confirms 50 and 100 kg bombs
https://es.wikipedia.org/wiki/Breda_Ba.65 - and doesn't mention, that Bredas were used after SCW...