It's only the liner that's nipping, unfortunately I haven't got a spare and I'm not keen to stop and drive to Norwich to get a new one. I have ordered a euro torch steel liner so next week I will have fun trying to graft it into the old non euro on the machine.
I have the same machine . Bought it second hand 25 years ago. In that time only fitted new liner , tips , a rotary switch costing a quid, two potentiometers for pennies and recently some smoothing caps.
It's had a lot of work over the years.
The qc sticker inside mine says 1985, I bought it a couple of years ago as a more powerful alternative to my snap on 130a I fitted some new caps a while ago. I have to say I'm impressed with the welds, it's way more smooth that the old machine & the wire feed is in a different class.
We have 1 migatronic at work, and it is horrendous to get a setting out of that doesnt produce a horrendous amount of spatter, multiple attempts of sabotage have been foiled in order to get rid of it or pawn it off to a different weld section.
Chap next door has one [not sure which model, I just know it's green ] in his workshop used to be his father's - like yours it lives under the bench and hasn't seen power for years.