This is a brand new resin model from Cromwell, though it was first available a few years ago as a metal model from Byzantium Models.  It ended up as the only one they produced and the master was sold on to Cromwell Models, who have now changed it for resin kit production.
Really a self-propelled gun, the T28 (also referred to as the T95) was built towards the end of the war to counter the German (and maybe even Russian...) heavy tanks.  Two prototypes were built, one of which survives in the collection of the Patton Museum at Fort Knox.  There are details about the vehicle development, along with scale drawings and plenty of photos in the excellent book "Firepower.  A history of the American Heavy Tank" by R.P. Hunnicutt.

The model itself is quite straightforward, and while there are not too many parts, the detail is excellent as we have come to expect from Cromwell.  One of the instantly noticable features is the twin row of roadwheels and track on each side.  Those outer track runs could be removed for transport by road or rail.  In fact, they could be bolted together and towed behind the vehicle itself.  A whole different meaning for 'combat tracks!'.  There is an mg ring around the commanders position, and both hatches on the roof can be fitted closed or open, if you want to add crew figures.  Some flash to remove from between the roadwheels, but nothing difficult.  The main work is in removing the moulding plug from the underside of all four main track runs.   It's a bit tedious but take care and you won't damage anything else.  The large gun and mantlet is cleanly cast, still in resin.

All in all a very different looking model, and certainly one that will stand out in a small scale vehicle collection thanks to that double run of track.

Available direct from Cromwell Models in Glasgow,Scotland