Villa; What are you saying about firemen: That's a great clip.
Just a few points on prep work before you get going. some 1927 house still were balloon framing, so you are looking for cavities between the studs on the gable walls at the ceiling level. They need to be blocked with wood, plywood, drywall or what ever.
All holes drilled thru wall plates for wiring should be chaulked with fireproof chaulk. Pot lights should be the ones rated for insulation.
If not they need a box built over them about a 1 foot cube lined with drywall. Insulate the cube with batts. and then I would put down 6 mil poly for vapour bearier as you likely don't have one now. Tape the joints with red Tuck tape and stick down the edges with acoustical sealer. Yes it is a pain to wrap the joists and walk on later is a neat trick too. You can staple in place on the joists.
If you stop all air flow from below you get full value for the insulation.