you can get a new grill kit so you can have the tube elevated and the grill up for the PMCS of the engine fluids, the balistic window that swivels? the extra links on the front deck, the door locking mech on the back door, individual track links, complete interior etc etc etc. I can't wait to order this stuff it'a an all out attack on the gun, I'm also gonna do another Paladin with the a-3 interior kits but I'm going to modify the heck out of it to make it modern.
http://squadron.com/ItemDetails.asp?item=EU35319
http://squadron.com/SearchResults.asp?ScaleList=35&TypeList=4&ManuList=everything&Key=Artillery
http://squadron.com/SearchResults.asp?ScaleList=35&TypeList=everything&ManuList=everything&Key=M109&Submit=Go
these last two were from :
http://www.greatmodels.com/ just use a search for: M109
these should get ya fired up and ready to get on those sights!