I’ll say it again.
Clothes sizing pre 2006 was based on post war sizing. That’s why it was smaller.
However was no ‘standard’ size 12 etc. Each individual shop has their own set of measurements which reflect their target market. This is true now and was the same 40 years ago.
I’d love to know where people are finding these ‘charts’ as the only reliable standardised source is BSI and they cost a fortune, and are copyrighted so not freely available on Google.
The change came in 2006, but Mand S size 12 is very different to River Iskand size 12.
AND, for further info, all manufactured clothes are made with ‘ease’ in, to accommodate the different sizes within a size 12/14/etc.
This explains it a bit
en.m.wikipedia.org/wiki/Ease_(sewing).
But all the charts and arguments in the world make no difference. The key things are:
Accurate anthropological charts are not in the public domain.
Each shop has their own definition of a size measurement depending on their target
market.
The only change in measurements hapoened in 2006
Clorhes are made with ease to accommodate a range of sizes within set measurements.