Seasider

I am most grateful to both responders for putting me on the right track, but I'd appreciate a little extra guidance. One side has three circles side by side - see Lock Side 1 photo. The two outer ones are matched on SIde 2 - see photo. The small centeral one on Side 1 is engraved with the letter S. Which of the five should I tap out, and from which side? With thanks again.

My 1970 Herald 13/60 came without a key for the boot lock (which I understand opens also the glovebox), so I got the correct replacement barrel and keys from Moss. Having removed the original assembly from the boot lid, I'm left with the top section, from which extends a square steel spigot, to which the original barrel is presumably attached. I can't see a way of removing those two components to fit the new barrel. Any thoughts? With thanks in advance.

Are there any photos/drawings/illustrations/instructions out there showing how to fit replacement inner (metal-edged) and outer side-window seal strips, using their different types of clips? With thanks.

I've noticed that with some Herald 1200s, the standard engine has been replaced by a 1500cc engine from a Triumph Spitfire. The pros seem clear but are there any cons? For example, does the replacement engin accept the 1200's existing clutch and (not sports) manifold downpipe?