Hi Steve
There were more than two types of Bristol 170

....Infact SAFE Air themselves operated the 31 and the 31M which would mean two models just for that.
The model changes are extensive but the other variants will evenentually appear
To make the shorter versions means remaking the whole of the front end inside and out, plus many other changes....effectively a whole new fuselage. The project is called a Superfreighter so that in itself says that's all it is and as it stands is a huge project....
I did a feesabilty mock up a while ago of a 31
As to SAFE Air......there are probably as many SAFE pics as all the others put together
No shortage at all on those...dozens of pics on the net
Garry