For logistical reasons, we are currently a pure mail order business and collection is unfortunately not possible.

The films always have a DX code, but the code is random. Since recycled cartridges are used, the code is sometimes ISO 100, 200 or 400.

The code is easy to change, you can find my instructions here.

The films are wound so that they all have 37 frames per roll.
We wind an extra image, as our bulk rolling process results in the last image beeing half exposed.

Film loses sensitivity with age, i.e. the ISO decreases. To expose the film correctly years later, you have to shoot it at this reduced ISO. I have determined this and specified it as True ISO.
The film can then be delivered to the lab and does not have to be pushed or pulled.

Example: Kodak Vision1 500T actually has ISO 500, but it has lost sensitivity over 20 years and now has a True ISO of 100.

V3 is new film, fresh from the manufacturer. V2 is a little older, between 5 and 15 years. Accordingly, it has a lower ISO and a slightly different look.

No, if they have been exposed to True ISO, the films can be sent to the lab as normal without annotations.

If you develop in C-41 at home, then you can develop regular C-41 films (Kodak Gold etc.) together with ECN-2 films without any problems.