Yo, that's awesome and incredibly sweet. There's actually a centralized repository nowadays with all custom levels for the game, here: https://marbleland.vaniverse.io/
Pretty sure you can find your levels on here.
LanceH
I still have the levels, though I shudder at the thought of opening quark to edit them :)
Incidentally the cake only existed for about 2 minutes while we got a photo of it, then it was cut up and devoured by ravenous 4 year olds.
It was a fun little community making maps for the game.
Pretty sure you can find your levels on here.