Good to go, tks!

I think it's still the F last. There could be last variation with some being wider than others. I've noticed this on my EG 888's (even though EG says they are all exactly the same) and I wouldn't be suprised if Vass had this as well especially since they are more handmade than EG's. Great shoes regardless! Don't fret and wear them well.

look the same

different shoes are cut and made in different ways, but it is all about the fit as you wear the shoe from the inside external measurements dont mean shit

then you better go bespoke then, but even then there are these differences from shoe to shoe and style to style

but if someone can see the difference when you are wearing them from the sole then they have bloody good eyesight

Hi theyare. That Chelsea is a beautiful shoe, to my taste probably the most beautiful Vass makes - and yours is definitely F last. I have a UK 43 in New Peter (or P2) and in F too, so I held them up for comparison with your pics. The New Peter is less tapered at the waist and all together more 'parallel' as opposed to 'waisted' along the sole. There's no mistaking the difference.
I can see the variation between the two Fs in your pics, and I'm surprised it's discernible to the naked eye, but I guess it's simply because Vass are hand-made shoes and no two will be perfectly alike even when the same last and style. Again - those Chelseas are stunners. Wear them in good health.

The waist of the shoe is not depending on the last, but is defined by the way the insole is cut. The outer sole will follow the insole.

In the forefoot and around the heel the last has a well defined edge (feather-edge), so there is no doubt, as to where the insole gets cut. When it comes to the waist, in particular the inside waist, there are no edges, it is rounded and soft. So it's at the shoemakers discretion where he places the cut. The narrower the waist, the more curved the line is, the more difficult the "˜making "˜ (attaching the sole) becomes. (A shoe with a narrow waist gives more support to the foot.)

Traditionally shoemakers in Central-Europe did pay very little attention to the waist. Even well-respected firms frequently produce ill-defined, sluggishly cut waists. Judging by the pictures, I have very little doubt that both pair are made on the identical last. The fact that the new shoes have a narrower waist, points either at different "˜maker', or. presuming both pairs were made by the same person, that his skill-level has improved.

Something similar happened to me too, a pair of shoes and a pair of boots, same size and last (and same lasted trees), one is perfect and the other is tight.

Look to the (high) instep, the difference may be there, and in the amount of 'give' the lacing affords there.