So after buying my '74 beetle at the beginning of the year, he's almost ready to be registered.

I drove him back from the mechanics after getting his RW, and stalled him at the petrol station (had just got my license the day before, in my defence!). After that he would conk out whenever he was at idle. A very stressful drive home!

His 'idle wire' was loose previously when this was happening, but we fixed the connection about a week ago. Though the whole wire looks a little old. I think perhaps the stall bumped his wire loose again. We have altered his idle to a slightly higher rev-range a few months back as well.

What could be causing him not to idle? Should I just replace the idle wire?

HOW did you alter the idle??

if you adjusted the screw on the cam - then this is wrong

You need to adjust the mixture and by pass screws on the side

Please read here
http://www.vw-resource.com/tune-up.html#idle 

ok, I'll let my boyfriend know that adjusting the screw was a bad idea. Thanks for the link.

Does this explain the stalling?

It "could"

You need to do a tune up to get a base line to work on.
Set the valves, timing and then set the carb

There are lots of reasons it could be stalling
2 most common I would say are poor state of tune and air leaks

Tell us how you go after the tune up

got my old man to the mechanic (Tony at Volksworld in Moorabbin, Vic), and $560 later, he's running a lot smoother. Seems like he just needed a tune - not surprising since its the first proper one he's had in at least 4 years...

thanks for the help and the advice

Glad things are better