Chrom, can you pay someone to stain/finish coat the wood? Will FIL accept a per hr wage? If not FIL, maybe one of FIL's friends?
I have done staining at night, in damp weather, not the best but for some beginning coats, it works.
My final top coat ((Urethane satin or gloss) is done when conditions are right. The not so right conditions, where bugs or moisture are problems, most imperfections can be buffed/sanded out or touched up.
