Rare Flail

[sapper740]

I don't profess to be an expert in WW II armour although I have spent a fair bit of time reading reference books and on the internet searching out info and pictures of some of the rarer vehicles and AFVs. I found this untitled pic while searching for info on M31B2 T2's. It is either an M3, or M31 with a flail set up that I've never seen before. The power unit for the flail is obviously mounted on the rear of the tank as evidenced by the multi-segmented driveshaft travelling up the right side of the M3. It would have been a bugger to maintain, of which I'm sure most likely led to it not being accepted for use. Does anyone have any info regarding this unit? If not, just enjoy the pic for it's rarity.