Self-propelled artillery is tricky. The M270 MLRS appears to mainly fire cluster munitions, so I'll save it until I deal with bombs. The M142 HIMARS appears to be similar. The M109 Paladin seems most in need of a full treatment:
M109 Paladin
ST/HP: 152
Hnd/SR: -3/5
HT: 10f
Move: 1/17
SM: +4
Occ: 4S
DR: 50
Range: 216
Loc.: 2CTX
The TL9 160mm howitzer from
Pyramid #3/37 can probably stand in for the main gun. DR is based on Google saying it has
1.25" aluminum armor and another source saying aluminum provides about 60% of the protection of steel.