Magic realm lot

I'm not quite sure what you're asking and I'm not sure what the restrictions are with the legacy version but I'll make a stab at it. Can you save the lot to your library rather than the public gallery?
Open the gallery and choose the library tab up top? That's your personal library and if you save a lot or household there you should be able to use it in a different game later.

@wrenstales @Catzilla if I remember the legacy edition doesn't allow access to the gallery, but it should allow for saving to a players "My Library".

I have saved it as a lot in game. Where do I find it in the sims4 folder?

I suppose you could try sorting your tray files by date and look for the most recent files.