I just picked up a pretty old (pre-1970, I think) Epi Crestwood.
The nut is broken and it needs to be re-fretted. It's in pretty good shape, but I don't know the first thing about these guitars.
Could anyone help me determine it's worth?
I'll post a picture in a minute..

It's hard to say without the price book. It could be quite valuable. Being that it is pre 1970. I don't think the sunburst was a rare color but I could be wrong. A quick check on eBay had two listings. One was $2000 and one was $11,500. I think it would be worth a serial check and a trip down to gruhns. I would imagine in current condition probably $700 to &1200.

Right on.
How would I do a serial check? Thank God it's still on the guitar.

Try this:

http://www.guitardaterproject.org/epiphone.aspx

Ahhh!
It's saying that the serial isn't recognized. I think it's an incomplete SN.

Ok, so it's apparently an Epiphone ET-275. Some sort of spin off of a Crestwood, I guess.
I'm baffled by this guitar. I can't find ANYTHING out about it.

And it's also a 1975 model, from what I was told by it's original owner.

I thought it was maybe a 70's rig. I noticed it was missing the tailpiece that has the E on it. Being that it is a 75, its probably not too valuable but it doesn't make it any less cool!
It will be a fun one to mess around with. Depending on what it has for pickups it probably sounds just like a Cresty.