I’d written a long post and then it all disappeared.
Well done on finding your ignition issue btw! Those Podtronics
units are a good buy, mines been on since 2007 and not given me any issues.
Re the split pin, you’ll know if it’s there when you remove the cover, it’s inserted via the feed side to the head so you will see the legs popped out in front of the rear posts.
The rocker boxes on these were a half assed affair. A great idea which was spoilt by them not addressing the central mountings properly, the covers are easily over tightened because there is a gap underneath the central mounting points, in the least you will want a fibre washer underneath the washers.
Over tightening causes the boxes to spread and deform.
I normally glue some 80 grade emery to a sheet of glass, move it round in a figure of 8 motion and turn the cover a 1/4 turn periodically, this will reduce the chance of the cover being planed unevenly.
Dress all edges ( which will now be sharp) with a needle file and a rose bit for the holes. Nothing too deep, just enough to stop it cutting the gasket. Also remove the studs in the head and check for flatness, if in any doubt lightly dress these with the rose bit also.
An alternative to the gasket is to just use a silicone/RTV sealer, still dress the surfaces as before but a finger smear of sealant does just as good of a job and saves a packet in the long run. This is what I now do and has never leaked since.