The primer bulbs on these are particularly robust, I find it very rare to come across a split or hard bulb. Must be made from some good material because some of the ones I end up with must be about 40 years old
I've got a 'project mower' in hand just now, so that I can do 'how-to' write-ups on a few repair techniques; a 1982-3 season Mayfair MK326A1 full crank 160 Ute.
The primer bulb was a bit hard/stiff, so I gave it the Armor-All treatment [which I've also had occasion to use on hoses; e.g. oxy set twin hose], and it did work very well, as expected.
