And no matter how much you extend the life of an already old extinct bulb, it will inevetably die and an alternative will have to be saught.... Or perhaps you will be dead by then and your kids will nurry you and your anciant equipment in the same box.
So a better solution is to adapt now before it becomes a problem n tjis will save more brain cells in the long term.
Sill a helarious thread... Oh btw my front door light has a 220V bulb running on 110V... I put it in 38 years ago n i have it on every night from dusk to dawn... So yeah your technique works fir some things but still very impractical for this application where color temp n other variables only complicate an already complicated system...
Adapt or dump the extinct for a new old enlarger... They are dirt cheap these days n even found by the curb on trash night.
A varey entertaining thread for sure.