You might have noticed in that list that the now almost-universal Speckled Wood wasn't seen until a holiday in Somerset.
PB amd HB Frits in north Norfolk were no great surprise and we found them soon after dad got his first car. I am certain that the HB Frit in Pretty Corner woods was not a mis-indentified DG. Amazingly, although familiar with Grayling along the dunes of NE Norfolk, I never saw DG Fritillary there. Maybe they weren't there in the 1950s. Indeed, in those far off days, it wouldn't surprise me if High Brown wasn't generally the more widespread and common of the two similar species.
In the late 1940s and early 1950s I would see the occasional but scarce Comma - hardly likely to be a misidentification. Not of course scarce these days
The single White Admiral sighting (and I admit, capture!) in the Broads remains a mystery. White Admirals are of course established in the Broads now so despite the perception that they spread in the second half of the 20th century, maybe they were in tiny numbers all the while.
EDIT: I can now tie down the date to 1951. It was a well worn individual on a bramble flower so I took it home alive to see its legendary graceful flight in my bedroom. I can visualise that room now and it was in the house I lived prior to move in February 1952. It was early August (dad was not working) so was almost certainly the weekend of 4/5 August. Exact locality TG454149 which it can be seen is very close to woodland (the obvious origin) although what is mature woodland now was little more than scrub in the early 1950s.
Silver-washed was caught in my garden, presumably a stray from woods not too far away (which without transport, I couldn't explore. They were mostly private in any case , eg Fritton Woods).
Many of my "firsts" were deliberate efforts, eg trips for Large Heath, Scotch Argus. But one of the accidental firsts was when I landed a glider at the disused Martlesham Heath airfield near Ipswich. I hadn't planned to land there when I had taken off - can't recall now where I was trying to go. But I ran out of luck (or skill) and much to my annoyance had to land. The old runways at Martlesham beckoned. Usually after landing a glider in an unusual spot your are immediately surrounded by hordes of kids who appear from nowhere but on this occasion all remained quite. Except..... the heather to the sides of the runway was alive with Silver-studded Blues and Skippers. I crawled on hands and knees and quickly identified the black undersides of the antennae of some of the skippers - Essex. I suppose it was just as well that nobody saw me on hands and knees beside a glider
They might have wondered.....
I quickly forgot my irritation at having to land the glider where I had not originally intended.
Jack