I understand your pain, but
there are hundreds of parts in most of our inventories, and we can't print up instructions for all of them. When you go to an auto parts store, most of the parts do not come with instructions. You are expected to use maintenance/assembly manuals and experience to do the replacement.
If the manufacturer doesn't print special instructions, there is probably no way a small dealer can handle that requirement for everything. Most of our smaller dealers are very knowledgeable and will gladly help you out, if you ask. The big dealers won't or can't.
Having said all that, incidently, I do print hand drawn diagrams of the body mounts. I have not done the core support, as the 67-8 CS kit I use does come with some...
and this is why I would rather sell to my customers face-to-face and not mail order. It saves a lot of confusion and hard feelings.
I recomend you do not give your supplier's name, as requested by someone else on here. It could cause some unnecessary negative reactions.