much slower if at all and no power.

On the up side you could be the first to convert your cruiser to a 24v system (imagine a dual battery setup). By the time you go through that hassle and expense you might as well mount up a 24v Warn, Superwinch, Ramsey and have an electric motor that was mfg in the last year or two instead of 50+ years ago.
If you go that route make a DVD, I'll buy it just to help offset the endevour.