The Sherman I Hybrid:
The reasoning behind the production of this model of Sherman was that a cast hull (like the Sherman II) is cheaper than a welded hull (like the Sherman I). Chrysler started producing these Sherman Composites (or Sherman I Hybrids) in 1943. From what I have read and seen from period pictures, 33 Armoured Brigade had a relatively large number of these hybrid models. Mechanically they were identical to the basic model M4 Sherman - or Sherman I in British Army parlance.
I had decided I fancied giving converting some of these style of tanks for my army. Nowhere I spotted had the hybrid models in 15mm scale, so I picked up some Sherman II models from eBay and set about attempting to convert them to Hybrid status.
To do this, I decided it would be easier to make the rear hull more angular.
Here's the base model Sherman II from the Battlefront website.
As opposed to the standard Sherman I
See the difference between the very curved and rounded top Sherman versus the very angular second picture? Sherman I Hybrids combine these two with a rounded front hull and a angular rear hull.
And here is my attempt at changing this into a cast front hull and welded rear hull tank:
Obviously, this is stage one - which was to green stuff up along the curved rear hull sections. The other thing these three tanks were missing were the applique armour plates that were added on the lower hull and turret to protect the ammo storage and gunner.
These I clipped out of thin plasticard: