reply to u/Minimum__Dot1795 at https://reddit.com/r/typewriters/comments/1rx45d7/imperial_70_can_i_use_any_spools_wanting_to_try/
I'm not sure of the internal diameter of yours, not having used Imperial spools before, but some of the cheap plastic "Universal Spools" have removeable plastic cores that may allow you to pop them out and be compatible with your machine. The one's I've got have a 3/4" or 19mm diameter hole and are meant to be used with Remington machines instead of their metal spool hubs. (Example: https://www.amazon.com/Universal-Typewriter-Typewriters-Replacement-Compatible/dp/B0D9P2P2Q7/?th=1)