Fretting over Fireflies

It's all Scott's fault.
We were happily playing some I Ain't Been Shot, Mum a few weeks ago. My Canadian Sherman troop was advancing to be ambushed by his StuGs and he has to point out that my Old Glory Sherman Fireflies have cast hulls and the Canadians only got the welded hulls.
Now my lovely Sherman troops were like ashes in my mouth. With a problem of such Gordian complexity what was I to do except loose sleep?
So I went to my friends, who are much more well read on the arcane technicalities of such things and asked them. I'm not a tread head or rivet counter by any means, but I do like to try and get the look of the thing right, if I can... without too much fuss or expense.
Much emailing ensued and 30 messages later it boiled down to this:
Apparently what I have are Firefly 1Cs. And the 1Cs were issued to Canadian armoured units in Italy and even used as replacements in Normandy. (The numbers of tanks knocked out in Normandy meant that the RCEME units were sending whatever they could fix back to the front and the tank squadrons were happy to get them! So any version of the Sherman would be appropriate.)
Another suggestion was to take the turrets off and turn them into Grizzly (the Canadian licence built version of the M4) Kangaroos to tow 17 pounder AT guns.
I would like some Kangaroos.
With the Plastic Soldier Company M4A4 and Firefly set on order for the store I realized I could get two boxes and that would give me enough to bring my Canadian armour up to a full squadron, even if I did turn the 1Cs into Kangaroos. Four troops of Shermans and Kangaroos! Visions of Operation Totalize danced in my head.
And finally after it all settled down I realized I could just swap the turrets with some of my M4A4s.
Now to figure out how to make the empty turret ring on the Old Glory model look like the troop compartment of a Kangroo....

....and get them some 17 pounders to tow!