I don't know that answer for sure, but here is what I do know:
1- I've upgraded a bunch of CP's and have used the s/w loads from Nortels website for 100/150's interchangeably.
2- S/W level in both units would have to match to even consider the idea.
3- You are not going to wreck it by trying, it just won't restore. Backups and restores take time, so you will lose time if it doesn't. If you give it a whirl, post the results....I'd be curious.......