Nothing like that supposition at H&H. The Out Inspection/acceptance station was a small room that was originally part of a corridor between the main work area and the rest/tea-room. So when it was tea break time (or NAAFI* break in UKMIlitary parlance) the staff just walked behind the out inspector and into the tea room. THere really was nothing bespoke about a No4T or an L42 believe me. They were treated as specialist tools for doing another job.
* NAAFI = No Ambition And Fxxxall Interest