We didn't use boom to lower to ground- just to get it into cockpit.
Then we had yard pick it from the cockpit with a jury-rigged setup on the travel lift.
The load is on the mast and topping lift and halyards not the boom.
I've seen an Atomic Four pushed up an extension ladder into the cockpit with 3 strong folks.
If you have access to a crane to lift from salon floor that should be cake.
Good luck with your build- Alma's A-4 runs much better than new.
.010 over pistons and CNC bored cylinders make for a better block than what came out of the factory.
Even with many NOS parts from eBay the cost was over $1500.
Pistons, rings, valves, guides, crank and cam polished, valve seats cleaned up and balancing...
IT was a real Covid-Project last Winter and Spring. It kept me out-of-trouble.