mk 1 golf tick over

I've got a 1980 mk 1 golf cabrio and I've had a problem with the tickover since I've had it

it wud tickover til u turned it off then when you restarted it it would not tickover

so today I decided to have a look,,I tryed turning the tickover up but could not get the tick over screw to move so I took the carb off to find a spanner to fit it ! however I cant get the tick over screw to move so I put the carb back on !!

now it wont tick over at all !!! it starts and revs ok then cuts out as soon as u take your foot off the gas……then to make matters worse ot wont re start just keeps turning over !! then if you leave it 5 mins it will start again !!!

any ideas ???
do I need to put some sealent rnd the base of the carb before I put it back on ??

also is it worth me changeing the plugs points condenser leads etc ? plugs and points look ok but condenser looks old !!

help !! its doin my head in now :mad: