Bartek,
Can't tell You much about other Your questions, but have seen a Czech made resin conversion kit for 1/35 Skif MT-LB into SNAR. As I remember that one had Czech markings as well. Sorry, don't remember producent name, but surely seen this over the I-net.
Hope this may help.
Sincerely, Alexey.
http://www.acemodel.com.ua (Europe)
http://acemodel.tripod.com (America)