Any reason you need to get oversized pistons? When I have done it in the past, I've found there are three sizes to piston rings, depending on the wear. I've just measured the bore size, post honing (BTW, used a dingleberry hone as it wasn't bad), fitted the corresponding piston ring sets to the stock pistons and everything worked fine.
Where abouts in the world are you from? Reason I ask is that country dependant, VW put different engines into the golfs. You mention that you have a 90hp injection engine. In that period, in the UK, the only injection engines the mk2 had were the GTI engines, both over 100bhp.
However, there are a lot of similarities, for instance, the first thing I'd check would be the coolant temperature sensor. This is (possibly) a blue sensor, usually mounted to a flange on the head where the top radiator hose is fixed. Get the car running normally, then disconnect it, if the idle changes, it's working ok, if not, then there is a problem.
Well, Hamlins in Bridgwater used to do all of the machining work for TSR back in the day. I might start there. Also, the likes of Retro Resus in the same area would probably be able to help too.
Calipers off and renewing everything which is good. The bad bit is that the hoses have seen better days.
No issue, easy to change.... Wrong. The hard lines are practically welded to the hose with the captive nut beginning to defom its so tight.
Cut the clip off to get better purchase but no luck. Have saturated in wd40 for now.
Apart from trying some heat has anyone got any suggestions?
You could get a bit of copper pipe a cutter and flaring tool and use a connector, so cut off a bit of hard pipe on the flexi, make a new piece and use a connector.
Have to agree on this one. I don't think there's been a single original brake line on a mk2 I've done in the last 10 years that came off without me having to renew it.
As above, get some copper line, some M10x1mm connectors and you'll be away. If it's a front line, you could reproduce the whole thing, they aren't particularly long.
There are a couple of people who do plug and play options. If you go on the facebook group, most of them are on there, put a shout out and I'm sure someone will come to you.
And the air con was a rather large ball ache, but ultimately worth it. Was lovely driving around this summer with the windows up!