OK, so here's the deal. Brand new clutch master cylinder from Classic Swede (click link below for details). I have 2 of them.
https://www.classicswede.co.uk/Clutch_master_cylinder_Volvo_200_series_240_260/p1733344_8407173.aspx
Be aware it's not a direct bolt-in as the thread on the hard line pipe fitting is different than original, and it requires a DIN (bubble) flare on the line. Comes with new nut, so you'll need to cut the end off the clutch hard line pipe and put the new nut on, then re-flare the end of the pipe. Or you could make up a braided flex hose using AN fittings or whatever to suit your project.
Also, I felt the pushrod was a bit too short as the clutch pedal sat a bit lower than the brake pedal. I modified the rod on one of these to extend it so the clutch and brake sit flush. You can buy the modified or the original one. They are both brand new. $40 each. I think I paid close to $100 each for them some time back. I ended up going with a 740 clutch master with the remote reservoir. Pick up Daylesford or I will post anywhere in AUS for $15. Or I can deliver to the Volvo Club of VIC night meeting in Heatherton on the 1st Weds of the month.