so pushed it in and on odd thing happeded. Engine would barely idle (very low revs). Fine with higher revs, no misfire or anything, just idle problems. It was very late so I packed up and hoped for the best at the M.O.T this morning. Problem still there this morning but improved a bit when I arrived at M.O.T. station then back to low revs again. Engine had very low revs during M.O.T. but.....passed 
. Been looking at Haynes manual for a while (totally unfamiliar with the 360's just 340s B14 and weber carb). I checked the plugs, 1 and 4 sooty (probably from choke out too long?) so cleaned them. Looking around carb and throttle linkage I noticed what i would call a throttle stop (nut and bolt on the choke side of the carb) that looked like it was not touching anything. So I screwed this bolt out till it touched the choke thingy 
, this brought the throttle on ever so slightly and increased the revs so the engine revs at idle are now a steady 800ish. (I think the choke is not affected by this adjustment)I'm going to check the timing before sunday to make sure it's not slipped. The car feels ok to drive and pulls ok. The only thing i can think of is that the bolt moved due to vibration while the car was running with the choke out, as the choke mechanism presses against it to increase the revs when the engine is cold. Have I done the right thing?
Its a solex 175 carb
I ended up turning the throttle stop screw back down again and adjusting the idle screw on the carb to get it right. (I had tried the idle screw the day before but it had no effect on the revs and had left it where I found it). Maybe there had been a blockage in it somewhere. I went to York on Sunday and the car ran fine. I did try putting super unleaded in it, just in case the petrol in the tank had gone off a bit, as the car hasn't been run since about October last year.