It's a Chinese B1.
Whether it is worth fixing up is entirely up to you and what you want to gain from the exercise. From a purely monetary point of view it's not worth fixing up so don't waste your money.
However, from a tinkerer’s point of view........ If you view this as a project rifle from which you want to learn something, then it may be worthwhile. Sometimes the knowledge and personal satisfaction gained from working on these rifles, without the fear of stuffing up a high end rifle, outweigh the money spent, within reason of course.
A few examples:
Project Cheap Chinaman - BAM B3-3 ~ Air Rifle SA Forums
HFT on a budget ~ Air Rifle SA Forums