Re: oil level dipstick..
I think the dipstick is not relevant. Oil level in a Lister and most listeroids is determined by the top reservoir being full, as it is automatically via the oil pump. The oil quantity in the lower sump should be about 1/2' below the removable cover in the lower sump.
I have never used the dipstick in my Listeroid. A real Dursley does not have a dipstick.....not necessary. Oil can never touch the con rod end cap, as that level is determined by the weir of the upper sump.
Dipper should be installed as a blade, not sideways, and needs to clear the bottom of the upper sump.
Cheers
Hugh