I recently bought a '72 jazz. Love it, but the strings felt a bit rough, so I changed them to d'addario's. Big mistake. The old strings sounded great, so Im trying to find out what they are, so I can restring the bass with the same brand. Here's all the info I have:
- Brass ball-ends
- Hex core
- No silk or cotton wrapings
- Strings are more grey than silver. Might be the age though, I don't know
- One string actually has what seems some rust on it... So stanless is out

???
Any help is much appreciated.