ISAA and other matters...
Originally, "ISAA"stood for "Inspectorate of Small Arms Ammunition" ; whereas a separate "ISA" (Inspectorate of Small Arms) looked after small arms; After WW II, the two offices combined, and for a short time the initials were "ISA&A" then only ISAA, meaning Now, Inspectorate of Small Arms & Ammunition.
"H32xx" is a label identifier...all SAA Labels had their own "H" design number, as did ammunition containers (Boxes, crates, tins, steel chests, etc)
Lot 23/45: NOT (as Tony correctly says) for delivery to the British Government, but an order for the Royal Hellenic Army ( Britain was re-arming the Greek forces in its civil war with the communist partisans). Britain supplied Greece with ammo from R^L (1945 date in full) RG (Lot numbers) and also GB, along with HN repacks ( re-chesting or checking) of other ammo (CP, DAC, U and U<>, Aussie etc).
The change from Mark "VII" to "7" occurred at different times for different factories in the period late 44 to late 45, and the labels would also be different from the contents.
regards,
Doc AV
AV Ballistics