Just bought a 1982 Volvo 345GL Special Edition. I already have a 1984 Volvo 340DL which I've owned for ten years.

Ahh I was watching that on eBay, good luck with it - looked like a nice car!

I gave it a wash as it had been sat for over a year. It cleaned up really well. The interior is all original and immaculate. I have an issue with the sliding sunroof. It won't wind back.

Unfortunately that's quite common with the factory metal tilt/slide sunroof - it'll likely be the cables at fault (which are no longer available). There are some plastic blocks crimped to them which break/fatigue. I'd be tempted to leave it shut!