Slow moving… real life getting in the way a lot here.
Anyway… got back to town this morning and cleared the calendar for a bit. Pulled the crank out of the kerosene and pushed a good amount of WD40 through what parts of the okay passages I could get to - I think I approximated the method
@Flyin900 did on his, sealing the bearing up a bit (I wedged a doubled up inner tube piece up against that race) there’s a definite point of entry and exit in there and it seemed like WD was coming up around the lower connecting rod - calling it a win, despite the tiny bit of rust staining.
And then some shiny stuff showed up.

But that’s for later. Engine cases replaced the crank in the kerosene to see if some of the gunk can get softened up a bit. Can’t take it to the machine shop in this condition.
While petrochemicals do their thing I moved on to the air cleaner reconstruction. I’ve got the covers so we can go function > form to an extent here.

Starting with a shell

Scraped down to the old epoxy and separated the front as I need to solve the missing “boot”.

1 3/8 PVC is about 2mm wider than it’s supposed to be so I “turned down” a section with some sandpaper, marked it up to get square in the tube

Epoxied that lip in, as this will give something for the 32mm silicone tube from a turbo kit (reinforced).

Horsed around getting the angle and height right.
Little epoxy on the tube>lip inside, and a base of black RTV to seal
Foam wrap with some E6000 in the channels, some globs of JB weld on the mesh frame to cap connection, and a piece of packing tape to hold it all together while it all cures.
Foam was a bit thick. The eyeball tape measure failed.
Function over form though. It’ll be hidden behind the covers anyway. I may run a single long skinny bolt from cap to cap just to tie it all together when it’s bolted on the bike.