Modern steel rims, cranks, etc are of low quality, because they are aimed at the cheapest possible price point.
From the mid 19th century, well into the 20th, the word "steel" was magic in Britain.
In general, the quality reached its peak in the 1950s, and quality started to go down around the early 1960's, as management kept searching for ways to make the bicycles cheaper.
This table is focussed on the mainline Raleigh/Rudge/Humber "Sports" model.
Actually, many well-known brands don't even do that; they order bicycle frames to be built to their specifications, with their name painted on, and equipped with parts from a variety of vendors.
Older models had a braze-on with a tapped hole on the right chain stay, behind the chainwheel, to secure a full chaincase. Some later models had simple braze-ons on the seat tube and down tube to secure a "hockey-stick" chainguard.
The luxury "Superbe" models were very similar, except for the saddles, the use of a locking front fork, and the inclusion of a Dynohub lighting system. Coffee color w/bronze head tube, bronze panel on seat tube. Red "R" front axle nuts & seatpost bolt, but not on the cotters.
(The Dynohub was also available as an extra-cost option on the Sports.) Lower end models, such as Dunelt, Phillips, Robin Hood, Triumph etc. Chainguard encircles chainring, bolted to tapped hole under bottom bracket. CPSC front reflector mount instead of lamp bracket.
A Raleigh bicycle of this era would have a Raleigh frame, made of Raleigh Tubing conected with Raleigh lugs, with a Raleigh bottom bracket, Raleigh cranks, Raleigh pedals, Raleigh headset, Raleigh handlebars, Raleigh stem, Raleigh seatpost, Raleigh hubs (Sturmey-Archer was a Raleigh subsidiary) and even Raleigh spokes.
All of these parts would have been made in the same factory.