Anyway, I've contacted TIPRO, and a Ukranian keyboard manufacturer called POSUA and they both said it's not their model. If anyone could have more information, please help!
I would do a typing video but it doesn't makes sense without the keyboard working properly, now when I connect it it shows random numbers when I press different keys, probably the way the previous owner had it programmed as a cash register.
Retrobrighting was good, I kept it for 48 hours or so and it wouldn's hurt if I did it for a bit more but I didn't want to overdo it since it was my first retrobright project ever!
Here are the pictures: