Leaking Toilet Shut-off Valve--Threaded Replacement?

[grwold]

My MOL's vacation home has a slow leak from the toilet shut-off valve.

   

The supply pipe is threaded copper--zoom in and you can see the threads.  But the local big box store only seems to sell compression replacements.

Should I ...
 a) look for a replacement that's threaded.
 b) get a compression replacement, and cut off the threaded pipe to repair.
 c) get MOL to sell the house ASAP?

I don't know the local code, so thought I'd reach out to the brain trust for recommendations.

Thanks for your help!

Greg

[Allen]

Amazon has Eastman 1/2 inch FIP x 3/8 compression Quarter Turn Angle Stop valve for $14.95

Al

[Snipe Hunter]

I'd probably cut it off and put a compression fitting on it but that pipe will have to get squeaky clean for a compression fitting to seal. Little hint with compression fittings... a drop of oil on the threads before tightening it down.

That's a pretty old valve. I'd think twice before turning it.

1/2 npt showing in stock at my HD. I'll bet it's in your too. They usually have a lot fewer of these but they should stock them. 1/2 in. FIP Inlet x 3/8 in. Comp Outlet Multi Turn Angle Valve

In stock at Lowes too Here

[lincmercguy]

"That's a pretty old valve. I'd think twice before turning it."

This. Replace it with a quarter turn valve whether you go with the FIP or cutting it off for the compression valve.

[blackhat]

I wouldn’t bet on that being 1/2” pipe and it’s brass. Hard to be sure from a picture but it could be 1/4 or 3/8 threaded brass. Standard pipe thread but measure the OD of the pipe nipple. Note that pipe is nominal. 1/2 pipe is not 1/2 inside or out. Don’t attempt a compression or any other type connection except the correct size female pipe thread. You won’t like the result. Order the correct valve if necessary after determining the correct size by measuring. Good news is that brass pipe threads very seldom weld themselves together. The valve body is brass and the nipple should be as well. It might be galvanized but doesn’t appear so.

[grwold]

Next time I'm back there, I'll have some tools with me to check it out properly, including to clean off the oxidation and to measure the diameter. Pretty sure I'll need to turn off the main before I can remove the existing valve. The house is pretty old--pre-'50s. From visual inspection that pipe's at least 1/2" OD, and looked like copper. But again, I'll clean it up & check it further.

Thanks for the "FIP" nomenclature. I wasn't aware of the proper term, to do a search, but was pretty sure what's there is threaded and not compression.

[Roly]

Next time I'm back there, I'll have some tools with me to check it out properly, including to clean off the oxidation and to measure the diameter.  Pretty sure I'll need to turn off the main before I can remove the existing valve.  The house is pretty old--pre-'50s.  From visual inspection that pipe's at least 1/2" OD, and looked like copper.  But again, I'll clean it up & check it further.

Thanks for the "FIP" nomenclature.  I wasn't aware of the proper term, to do a search, but was pretty sure what's there is threaded and not compression.

If you remove the existing valve before shutting off water, you will be wet along with everything else.  Make sure the water is off by turning on another faucet.  
I agree with Blackhat that is not what is considered 1/2" pipe, Roly