Worth a rehair?

[Subdolus]

Pics can be found here: https://imgur.com/a/6VV2GOB

My parents have this kind of awesome habit of remembering that I like antiques and that I like having instruments and things for them regardless of whether I play the instrument they pick up or not. They found this bow for $5 as part of an auction lot and gave it to me.

Aesthetics aside, as one can clearly see the finish is a mess and the grip is a bit ugly (but not worn through, only some missing edges; it looks and feels like old leather). I don't care too much about that as I don't need it to look pretty as long as it sounds decent. 
The stick is stamped Sofian Zapf and, under the frog, it's stamped Germany and weighs, if I'm rounding up, 57g. The exact weight according to the scale I have is 56.7g.

The frog doesn't match the bow at all and was probably replaced at some point; it's (the frog) super heavy compared to my other bows but it's not so unbalanced that it's difficult to use. The screw seems a bit too long as well but the frog isn't wobbly and it does tighten and loosen normally it just--sort of sticks out a bit more than the others I have.

Despite it missing half of its hair (and the hair that's left was put on badly, twisted in some spots, and at both ends there are bits of it sticking out as it wasn't trimmed or put in properly, feel free to roast whoever rehaired the thing probably decades ago, because even I can see it's a...less than ideal job), I did decide to rosin it up and see how it sounded.

It sounds pretty nice despite missing half the hair. Nice, warm, rich tone to it.

As far as I can see, it has no cracks or anything in it that would require repair.
Haven't had a luthier look at it yet, though my instructor took a look at it and gave it a spin and thought it'd probably be worth rehairing if it doesn't need any major repair. If I don't manage to catch them in when I'm there for lessons, I'll have them look at it when I pick up the other old bow I currently have in for a rehair and minor repair.