I may have a distributor for your car , have you found that the plate does not advance when vacuum is applied to your advance diaphram? ...BUT most likely the idle speed control box is faulty AND it can be opened and resoldered .. Do a search here for " Idle Speed Control Box ". remove it, it just unplugs, take the cover off , plug it back in and SLIGHTLY twist or flex the circut board while the engine is running ,, sometimes the hairline cracks reconnect for a couple of seconds while twisting the board and the idle will lower ,,, that's how I found out that my ISCB was faulty .. I did resolder mine and it worked fine .. I also have a newer ISCB if you find fault with yours and can't repair it , mine is a EURO 380 so the newer ISCB I have for U.S. models won't fit my 380 ..Good Luck..

Ben