So I've checked everything once again and I must admit, you're right.
There are some black markings on black cover tapes XL3 3G FM-V1.0 and 2038N-W1/578-V1.0 maybe that's something related to hw revisions you mentioned
After flashing all firmwares that I have here are my conclusions:
All N versions work as expected (what a surprise
)
All A versions - keyboard is not working or working very slow, no gsm connetion and battery indicator shows always 0% (but phone is not entirely dead - can be reflashed
)
All X versions (including polish one that you provided) work perfectly but they have one main disadvantage - Only SIM1 slot works - SIM2 doesn't (no indicator, no second imei)
in the end... foreign dual sim or native single sim
(or thrash bin
because all of this flashing has overwriten both original imei)