You can shock the purists and use nyloc nuts. Not usually necessary rhough.

Japlac enamel is pretty good. Reasonably petrol proof too. If sticking with aerosols, try warming the can and if possible the chainguard first. I keep a kettle and a hot air gun in the shed for this.

Missed the worst of the Mods and Rockers era due to youth at the time. Funnily enough there was a small group of us at school that used to go out for rides - My C11G, one C10L, one Honda 90, one CB 160 brand new (!) one Lambretta and one Vespa. I was particularly envious of the scooters' reliability. My C11G never quite made it up Porlock Hill.  Replaced it with an Enfield Crusader which was even more unreliable if you can imagine.   

RTV sealant is pretty good for sealing exhausts.

I live near one of the UK's best biking roads and also Scotland's most dangerous stretch of road (as was featured in a TV advert on hazards and safe driving).  As you can imagine, both are favoured by bikers, not all of whom live to tell the tale. Blue flashing lights are all too common.
Despite being a lifelong all year round biker, the racket every decent evening from poorly silenced and unsilenced bikes howling over these roads really annoys me. It really does not do the whole movement any favours to add to noise pollution. It's just adding ammunition to the anti-bike lobby which is increasingly powerful. We can be our own worst enemies.
And you'll go deaf!

Over the years I have discovered that most BSA owners interested in club activities up here are in the VMCC. I did try many years ago to gauge interest in setting up a Scottish branch but couldn't get the numbers.     

Definitely less fun, depending on your definition of goes wrong. I use my BSAs for long distance and critical journeys. Anything going amiss would be most unwelcome. My last breakdown recovery in 30 years was with my Norton. A none too old rear tube split and I didn't have the appropriate spanner in the toolkit. My fault entirely. The plus side was it happened outside a cafe so I could sit and eat an ice cream waiting for the van to arrive. Had it happened an hour earlier I would have been on tiny seldom used roads in the Highlands far from habitation or mobile coverage. Sobering.
     

The B40F is a bike that grows on you. Hang onto it and ride it. I miss my B40...