Found some pics on my photobucket site  when looking for something unrelated--as you do.
Is of alloy ring inserts to use comon seals like from DT250 & 360A & beyond.
Good idea for when the supply runs out of those big originals.
Best add i wasn't the one that made them & were already in a motor i ended up with years ago.
But oneday i might need to make some up myself as no longer have 'that' motor--or cases anyway.
Having trouble taking pics of P/bucket as won't attach then i lost all my text.
Screen shot might work. I'm sure i put these pics up years ago too but anyway.
Yep i see the circlip not at the arrow, but that's more important for the inner circlip so doesn't obstruct the oil fuel mix feed to the bearing.
Then again if it the visible outer one was around there it'd be retained more fully, or would it!!. Never mind, too late now.