Since we are giving suggestions on how to improve the set...
How about correcting Tamiya's mis-naming of it. With the external fuel tanks, it is an M113A3, however it should also have added armor plates to the front glacis, a series of footman loops and bolt attachments along the sides of the hull, and beefier rear ramp hinges and door handle, etc.
Or call it what it is, an M113A2, and leave the parts for the external fuel tanks out.
The rear idler wheel is still too low for either an accurate A2 or A3 though.