My Volvo Quick Reference Parts Catalog shows only two part numbers for 240 and 260 Girling Front brakes from 1975 to 1993. One p/n is solid, the other p/n is the vented style.

So, you should be able to find a new2you rotor set in a recycle yard. This means, of course, that you are RWA (ready, willing and able) to swap the rotors.

If you go that route, I would recommend replacing the front wheel bearings and seals, too. That's assuming that the ones now on the car aren't good enough to swap across and you can do the job without nicking the bearing surfaces.

There may actually be a leak in the junction block. Fluid low enough to light the warning light means air in the lines beyond the J-block, and that doesn't take much of a leak - just enough time.

You probably noticed that only one of the two fluid tanks was low. Running that way very long will cause the front pads to wear into a wedge shape, having full full pressure on one pair of pistons, and lesser pressure on the other pair. BTDT

Check the MC very frequently. Keep a 12oz can of DOT4 on board. Always top up last thing at night. Get a 32oz can for garage storage, the 12oz is easier to pour out of without spilling. Remember that brake fluid eats paint.

If the rotors are not seriously scored, get new pads from AutoZone, they are soft enough (and dusty) to wear to the scores. Cheap fix, I know, but...

Good Luck,

Bob

:>)