Aftermarket turbo failure on E23 - safe to drive at low speeds/ with slow acceleration?

HI everyone! I don't know much about turbos. I am considering purchasing a 733i 1980 with a Callaway turbo and am wondering if it would be ok to drive if I do not plan to go over about 60mph. Would I be able to drive at fairly low speeds with the original engine?
Would I be able to drive the e23 for a while until I can remove the Callaway turbo (or rebuild it - presuming that wouild cost thousands)?

And if I remove it, would i be able to easily find whatever parts I would need to drive it with the original engine (ie. different exhaust manifold or intake manifold, or etc?)

Thank you for any feedback!