I want to emulate Roman construction & imports with a priority only second to bullets, fuel & transport, in that order. Some things others will try to collect are of less use to us than the things which will last a very long time if we are clever enough not to imagine we can have another society where things are meant to break & be replaced or can be manufactured in the long term.
Example: The only steel salvage I do not want to sell are blades & things that can hammer a peg. Steel is something we cannot melt in the UK & ploughshares etc. will need to be bought or swapped. There will still be a market for contaminated crops, products & scrap.
Industrialisation followed a system which was not very much better than the Roman, which God is happy to sustain. Most notably Electricity & Gas saw use, God is unhappy with them. Woodwork became very advanced by comparison, also faucets, not much we think. Public baths were in use until recently.
What's wrong with this? very good.
This could be Kelvar for the duration of ammo. It looks better than anything the UK produced for centuries when Romans left, learn.