An issue with any tracked vehicle is 'track life'. The M7 'Priest' uses Sherman running gear and tracks (generally speaking), with probably a 5000 km life.
http://english.iremember.ru/tankers/...triy-loza.html
Though there are Shermans and Sherman-derived vehicles in museums to steal from, plus of course the team's caches would have tracks. There's a company still making Sherman suspension and track (as of a year or three ago), for a variety of industrial equipment!
Speed might be an issue: if your M7 is in Alabama, and the Bad Guys are acting up in South Dakota, the 1900 kilometers is gonna take you at least 79 driving hours. Redesigning the track, suspension, gearboxes, steering, etc. to allow higher speed (from a presumably more powerful engine) and survivable ride ... you might as well make a whole new vehicle.
Maybe: mount the howitzer in an open-topped version of the Cadillac-Gage Stingray 'tank'. At least twice as fast as the M7. All sorts of tanks in WW2 had "gun carriage" conversions, many just a simple rifle-proof box around the front and two sides. The Stingray was generally described (if I recall correctly) as proof against 14.5mm ammo on the front (so presumably just rifle-proof elsewhere, at best).
If an open top is important: the V150 carrying the 81mm mortar has an open top.
Nice to hear the artillery will be traveling with an escort (if all goes according to plan). Which, of course, it won't! "Where's the rest of the team? Where's the truck with the rest of the ammo?"
Hmm, regular crew for the M7 is 7 people ... increased to 8 after the 2nd World War:
http://afvdb.50megs.com/usa/pics/m7priest.html
I see a little trailer being towed ... either the M8 ammunition trailer (armored) or the M10 ammunition trailer (unarmored, open-topped). Either trailer was nominally "one ton" and could carry 42 rounds of ammunition. I've worked up numbers on the M8 trailer for my campaign:
"2 wheel trailer M8 in use since World War 2. 3 meters long, 2.25 meters wide; the armored box is 1.66 meters wide, 1.5 meters long, 0.66 meters deep (1.6 cubic meters). Empty weight 1200 kg, payload 1000 kg. The wheels are 7.5x20 or the usual 9x20 CCKW type. No running brakes are fitted, but a hand parking brake is installed. Military towing lunette ring on front."
"[The Armored Trailer, M8] is suitable for transporting fifty-four 5-gallon
Quartermaster gasoline cans or the following rounds of ammunition:
105mm howitzer, 42 rounds
75mm gun, 93 rounds
37mm gun, 360 rounds
Cal. .50 machine gun, 25,200 rounds
81mm mortar, 222 rounds"
The manual:
http://www.scribd.com/doc/150148927/...RMORED-TRAILER
Ah ha: the M7 didn't normally carry a radio ... it used telephone lines or just plain "adjacentness" to communicate with the FDC. Easy enough to drop in a modern tactical radio, and an operator.
Oooh, the manual:
http://cdm16635.contentdm.oclc.org/u...name/63358.pdf
You'll have to decide what ammo they have initially: giving them 69 rounds of tear gas and 44 rounds of propaganda leaflets would be mighty cruel!
One advantage of the M7: it's available in lots of miniature scales. Company B makes one in 25/28mm:
http://www.brigadegames.com/M7-Priest-156th_p_1936.html
Another useful manual -- not so much for the Project, but as a guideline for the world after the Atomic War:
http://www.90thidpg.us/Reference/Man...%20Vol%201.pdf
--
Michael B.