Yep, it's definitely a 5MB ProFile inside. I've opened up every single one I have (they all needed some work before I was able to use them), so I know them pretty well inside!
And just to be clear, my 10MB model isn't a regular 10MB ProFile, so I can't really give you any information there. It's a weird prototype that fits inside the Lisa's drive bay like a Widget, but all of the electronics are basically the same as the ProFile, just shrunken down and modified in terms of form factor. And since it's a prototype, it doesn't even have a serial number that I can give you!
I don't have it with me right now, but let me see if I've taken any pictures of it that I can share.