I can only see a green shirt and the red chambray. Both listed as L but with different sizes, as you say, Jdemy. I reckon these are sample shirts that were made up by Jake. I was shown a few samples of shirts and jackets when I visited his workshop. I ordered shirts from him according to neck size and sleeve length as per his web site. My shirts fit me really well so I was able to check dimensions before deciding that the Maarkt shirts were definitely too big for me. I reckon you can trust the sizes given because I've a hunch it is Jake selling them.

Got an email yesterday to say Jake's has moved to 58 Chiltern Street. Hopefully he will start producing some more shirts that appear to be out of stock on his web site.

My age old BD Baggies blue chambray shirt was looking a bit past its best and it was time to order a replacement from Jake. Yesterday I collected this and was again very pleased with the standard of his work. He is about to move workshop again, from the windowless basement where he is in Chiltern St to a fourth floor workshop in Archer St, Soho.

I still see his shirts as representing excellent value compared to the obvious alternatives and as my staple shirts come up for replacement he will be ‘my go to’. Mind you I’ve still got a couple of Brooks Makers blue button downs in their packets!

These look great.

https://www.jakesldn.com/store

Next time I'm over there (who knows when), I'll have to check them out,

I once had Harvie & Hudson try to make my some US style button-downs.  Fabrics were beautiful (DJ Anderson?) but they couldn't quite nail it.  But hell, this is about 35-40 years ago.