I've been looking through John Worrall's/Liz Turner's book "Original Morgan..The Restorers Guide" There's a good shot of a 1968 Plus 4 dash and John's Super Sport which is almost identical. None of the switches appear to be labelled. I always thought that the top "knob" is in fact a dash light which switches on by pulling out. (I've a similar one bought from Holdens Classic Cars which I was going to fit to my 4/4 Sport.) The lower knob.....choke or starter?
I'm sure there's a Plus 4 owner about to put me right!