Is it good practice to replace the clutch with a new one if you are changing the engine, or if the old one looks ok is it a good idea to re-use? Also does anyone know what size/type of socket I need to remove the clutch plates bolts, is it a spline set I need? Thanks
Bolts: may be splined, might be hex head. Clutch - depends how manky it is, but worth changing anyway if it's the first time you've had the engine out.
check the clutch plate for signs or oil contamination and wear, the cover spring "fingers" for wear where the bearing sits and the make sure the bearing is smooth. check the flywheel for scoring and get it skimmed if required, should cost £40 or so
also remember that the bolts should be replaced and are tensile steel. you can get them in a set from Volksbolts. pretty sure they are M8 and 13mm
I would replace the whole lot, if its age is unknown, daft not to, I think the kit I got was 110 quid, mine had hex bolts, replaced with new ones...
Other thing is that you may need to remove the clutch to measure it as the size may not be stock. Mine is a 1800 T4 but now has the flywheel for a 228mm clutch from a 2 litre. No way of knowing unless you strip first. Mine were spline bolts (the 12 point ones) and get yourself a flywheel locking tool if you don't already have one. They are cheap and make things a bit easier.
I second checking the flywheel it's supposed to have a defined groove pattern to help the friction plate grip