Thanks John, builder101 & Grendels

The main difference is the cockpit interior, but subtle differences are also on the exterior...

There now is a missing part on the Studio Filming model that is used for reference, the darker un-weathered square here:

the other side shows a completely different shape (the Jango Fett Slave 1 has this same shape on either side as does the old AMT kit of Boba's from 1980 onwards)

......but this still from the film shows the model 'flipped' to reveal the missing part....:

Zoomed, brightened 7 flipped back:

The FineMolds kit fills in the missing part:

John