I'm quite surprised nobody on here has discussed what a period correct fire looks like?
Surely if you are going to the trouble of a period correct extinguisher you would want to get the fire right as well? Otherwise it will negatively impact value.
I've seen a couple of poor attempts at re-creating this online but none have got it quite right as most have used DIY or after market options for ignition and fuel.
For those considering this much desired after market option you need the following;
Leaded petrol - not that modern crap;
Asbestos heat lagging that will easily oxidise and release fibre when burnt so you can inhale it while crying;
Date stamped magnesium based engine parts and wheels;
Matching numbers block;
Existing engine bay oil leak;
And most importantly all original wiring loom and fuse fox, ideally with exposed wires and cut down nails acting as fuses;
Don't forget that if you own a CSL you may not be able to rely upon power steering fluid as a fuel, sound deadening or perspex windows depending of if you are RHD or LHD
If you live in colder climes I suggest also running your heater on full when attempting ignition as that will aid the supply of fresh air, so you can really get it going fast.
If anybody has trouble following these steps I think
@Markos plans to upload a helpful step by step video.
Hope this helps.