I think I made it worse
Before my bad dongle was at least detecting correctly, but could not operate.
I've desoldered and dumped I2C EEPROM contents (using TL866 and 24LC256 config).
Here's binary fw from bad dongle.
It looks like some data there is good. You can see National ascii text strings for example.
Then I read same I2C EEPROM from my good working dongle:
From good dongle.
Interesting enough PCB actually was little different on good one, using 24LC256 in SOIC8 package, not TSSOP.
I've wrote EEPROM in bad dongle with this good binary. Module detected in windows, but was blinking LEDs in various patterns. And attempt to use it failed.
root@raspb:/home/pi# gpib_config
failed to bring board online
failed to configure board
main: Operation not permitted
Then I wrote EEPROM back to what was in it before.
And now dongle does not detect correctly, but gets default Cypress "unknown device" crap.
Let's see if any other samaritan want to dump EEPROM from good dongle to check my images.