The ones i was given today are a set of metric pairs 5,6,7,8,9,11and 12mm. No 10mm sadly
theres a date on them 1944 with an arrow…is that a MOD mark?
i wonder how many metric threads were needed in the post war years and I’ve never needed 7,9 and 11mm threads
the die holder i pictured i have bought on eBay looks to be the same brand “easterbrook” so hopefully it will work