I published my technical description of Bomb on the Wikipedia page earlier this week, and scoured the Sherman minutia page too. Please have a look and let me know if I've made any grievous mistakes.
Holy Roller is one CT number off of Bomb, even though HR is two months older. For a tank made in the middle of a seriously big contract, I suggest the M3 bogies are a bit of a tall tale. There are chronologies for use of nonstandard parts, but the M3 was inferior to the mid-production M4 VVSS (location of the return roller, absence of the track skid, and if memory serves, the diameter of the actual volutes from 7" to 8"). Perhaps it was changed during operational stock storage in UK. There were M3s and Rams in use. I've included a snapshot of a Ram without its track and Bomb's right rear bogie for comparison.
Speaking of tracks, B Sqn Sherbrooke Fusilier Regiment won a coin toss with A Sqn when 18 new tanks showed up in April 1944. The regimental history tells how the CO decided not to disperse the new tanks around the unit, but to completely reequip one squadron. The crews had about 4 weeks to get rid of the preservation greases and get the tanks running to peak performance. The attached photo came from Library and Archives, via Hal Skaarrup's busy Facebook page. Notice the type of track being installed.
