Erik does not handle customer support any more, he is way to busy with business. I have had success at buying parts that are not listed specifically on their site. But don’t make the conversation too long or complicated.
as for the kits, yes Imex really lacks at them and I wish they did better. I bought a kit long ago and it was really a collection of spare parts, luckily I had lots of Sherman’s already and knew what I was doing.
they are not that complicated so do your best to assemble it and post here where you get stuck and we can help you out getting it running.