this kit is a modified master grade MS-06J Zaku II ground combat unit. the right shoulder is the one that came with the kit. i just filled in the spike hole with plumbers seal and sanded it smooth. the left shoulder is a resin recast that didn't quite come as intended, so i had to improvise some battle damage. for all the weathering details, i used a tamiya weathering kit. i'm really pleased with the results. the machine gun came from a zaku 1 kit. the spkie shield is made from the shield and shoulder spikes and a few left over part from other kits
The weathering on your kit is outstanding!