ULA received, thank you very much.
Pending to do further testing on my ZX81 clone since now at least with the new ULA has been brought back to live (there is now picture and the "K" cursor appears again!) but it's behaving weirdly when typing any command (for example PRINT is shown as "OPJOS" and there are some graphical glitches).
Since I don't know if this could be caused by the RAM or even the ROM I need to do more testing.
Regards
EDIT 16/07 - Tested on 14/07 and confirmed that the ULA was behaving weirdly. Tested a known working 2C210E and worked fine.
Commented to oONosferatuOo and he kindly agreed to send another unit after providing pictures of the screen artifacts that this ula caused.
Will update once I fit the new replacement.
Regards,