I agree with most of what you say but I do disagree in one key area - instead of 'Signature', it is my opinion that 'Exclusive' fits in better.
The reasoning behind my perspective:
Signature implies that it is a unique version, and while it has an engraving on it, it's still the exact same device.
Exclusive, on the other hand, reminds me of something limited, that people want, the word itself seems to add value to the product because it's so heavily associated with glamour and luxury.
This is of course me entering the immense world of semantics haha but I think you get the idea why I believe Exclusive Edition would fit in better.
About the numbers, to me we could go three ways: one utmost minimalistic where 'Exclusive Edition' would be featured inside the kickstand (therefore not visible) and no number would be there; one with the numbers on the lower left (ie #001) and 'Exclusive Edition' on the lower right, both on the back of the device; and finally one where only 'Exclusive Edition' would be featured - it would be located on the lower right of the back of the Eve V.