The grab handles look terrible. There is an extra one at the trailing end on the LH side of the end doors. The door handle on the communicating doors on trailers and NDM is wrong at one end The end window glazing is a little too wide The door fault light is at the wrong end of one of the driving motors Some trailers and NDM have London Transport when they shouldn’t. There are no butterfly cocks on the earlier versions.
As for making them run....
Adding motors are relatively easy. There are two options for replacing the trailing bogies.
John Polley does an upgrade kit - not tried it but looks like the cars run really well. There is a little cutting and hacking though.
The other option is my mate Nigel as 3D printed 1938 and 1959/62 bogies as a direct replacement all you need are the bass bearings and 10.5mm wheels.
In addition to the early releases not having the butterfly cocks printed on they are also missing the black for the door seals, though that shouldn't be the most awkward thing to add.
I have a 1938 stock unit fitted with the Metromodels (John Polley) bogie upgrades. They do roll a lot better than an original (with metal clip removed) EFE bogie. One thing to be aware of is the result is wider than the original - with shoegear, slightly wider than the body in fact - so it's best to file down the new bogie part and the EFE bogie sides as much as possible to reduce this somewhat.