This build is based on one of Apophenia's wonderful doodlings.
I can't remember if it was his idea, or within his thread, or tripped over elsewhere as a google tangent to his work but he's getting the credit for the idea of one of the two dozen M-11/39s in Italian East Africa being turned into a Semovente. See
https://weaponsandwarfare.com/2019/01/31/carro-armato-m-11-39-medium-tank/This modification would require removal of the ridiculous one man/two machinegun turret and the anemic 37mm, to be replaced with the standard Breda 47mm AT gun (of which there were some - but not a lot - in theater at the time).
On the left, the standard M11/39 and on the right, the L6 Semovente 47/32 interior grafted into the M11.
M11/39 interior and Breda 47 - totally do-able.
Note: the 47mm recoil cylinder is 180 degrees opposite of the 37mm's.