Help with no power??

I know this is A body forum, and I own 3 A bodies, but I have a question about a car I purchased this year. 1970 challenger V code. I get far better results on this site than when I ask questions on FEBO. So here goes.
Pulled plugs and oiled cylinders, car has sat since 1983 in a dry garage. Waited a few weeks and slowly turned engine over. Fresh oil, primed it and wanted to try to fire it today, so we put a new red top optima in it, and when I turned the key, NOTHING?
We checked the wiring and I turned on the headlights and NOTHING? It looks like the fusible link going to the stater relay was replaced with a twist on plastic cased 20 amp fuse? I jumped the relay and the car turned over. But I have NO power anywhere?
Any ideas where I can start? I have a good battery ground.
Details on car:
1970 Challenger R/T
F8 triple green car
V code matching number engine
727 non matching
All original sheet metal
Retains almost all original parts
Right down to it’s 15” rallies and P/S oil cooler
NO IT IS NOT FOR SALE!