Try www.briggsbits - they seem to stock all kinds of parts for Briggs & Stratton engines.
For other lawnmower spares try "OldLawnmowers" - think thats right. I used them to find parts for a 1963 Colt cylinder mower and found them very useful. Apologies, I can't find the correct website name.
Mike Giles
April 2015
I can answer this question...
where con I get parts for a 1976 suffolk colt petrol mower?
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix lawn mowers.