Sadly much of British Industry was craftsman based rather than what we would call an industrial approach. This is not meant to be a derogatory observation it is instead accepting that the master tradesmen had incredible skills but it took too long to train them.
As an example and yes this is a made up rhetorical style example.
Rolls Royce is making engines and every engine is put together by one master tradesman and as he builds the engine he hones and shapes the parts to get a perfect fit. The engine is reliable, high performing but has little direct parts commonality with the engines Fred next door makes. Also each engine takes a week to make.
60 tradesmen making 60 engines per week in total.
Ford gets the schematics for the same engine. They realise the drawings allow for finishing and is not replicatable or able to use stock parts. While rolls is making 60 engines a week the Ford Engineers spend three months getting every part to work perfectly every time with no final finishing required. A month later the plant opens and 60 workers get trained to do a single task each. No worker knows the entire engine just the parts they have to fit. By now Rolls has made 960 engines and Ford has made zero. Next month Rolls makes another 240 engines and Ford makes 120. Every worker has been triple trained and all parts are now fully interchangeable. The next month Ford makes 60 engines a day.
Rolls is still making 60 per week. Ford is now making 7 times the output and every single part will work in any engine without extra work. The main workers are now better than the tradesmen at the task they do 60 times a day.
This is exagerated and sounds fake......only they did this over and over again. British equipment was as good as American equipment, in some ways superior, in others far worse. The Bofors gun is the perfect example. The Packard Merlin was as good if not better than the equivallant mark of engine.
For the British Army to have superior equipment it needs to drive the cost of that equipment down through industrialisation of the PROCESS used to make the equipment. For example if the AT gun production line was setup to be a Ford style factory, the new 6 lb gun is easily placed into production with maybe a week of downtime while the process changes. In fact the line does not need to stop just reduced output for a week while training happens. Then you do extra shifts or OT to catchup.
The 2lb gun was very good, it was however inadequate for infantry support and had a dismal HE shell and no Canister round. A 47mm for example would have been marginally bigger but offer a significantly better ammunition selection and usefulness.
I have seen this idea farmed out sooo many times and then shot down
Simply not true of wartime British production
My Great Aunt built Merlin's in Crewe - in 1940 she had been a bookkeeper in Ireland - in 1941 she was building merlin Engines in England
She had no letters after her name, did not possess years of engineering craftsmanship and yet here she was building arguably one of the most advanced aircraft engines in production
This would not be possible if Rolls Royce was not practicing the then latest mass production techniques
What is true that just pre war and arguable in the very start where existing small industry was leveraged for war production we might see this example of small scale factory issues using outdated techniques
But RR Crewe and other major factory's such as Castle Bromwich assembly dispute it simply by existing
As for ammunition - the USA was not producing cannister for its 37mm until April 1942 and HE for the same weapon until Feb 1942
There had not been a perceived need for it