Bike porn

OK, am I right in guessing the owner has kept the original cottered cranks? Possibly the chainring and BB too?
I am wondering about the pro's and con's of this. I've heard that keeping an old chainset increases the chance of the chain coming off.

equipment list:

Frame: Bates Volante - track - 1936
Wheels: 'Cane' sprints on Airlite large-flange hubs - single-fixed
Chainset: BSA 5-pin with inch pitch chainring
Pedals: Sheffield
Gears: Single-speed fixed inch-pitch
Brakes: N/A
Stem/Bars: Major Taylor stem with steel track bars
Saddle: Brooks B17
Extra details: Believed to be the machine ridden by 'Torchy' Peden at the London 6-Day 1937. Original matt black finish with gold lug lining

1" pitch detail:

whether this increases chances of flinging the drive I can only guess