Yes I think your right as from what I gather journeymen ALSO went sailing on the ship to repair any faults while on trial runs testing the equipments so small faults were rectified on board for the clients even though there was most probably a permanent sailmaker on board ,
It was the custom then to give a silver (trophy) for men who had done their time in the dockyard and as sailmaking paid very well and there was lots of work if you were good at it ,an awful lot started their own business outside and as I imagine he left after a promotion ,thus even though he left earlier , I imagine he may have been a chief of some sort (thus the silver BOX) which he may have kept his needles in ,and ,classified as a (master sailmaker) AND PROBABLY HAD HIS OWN BUSINESS OUTSIDE ALREADY ESTABLISHED years before ,, as many did even while I worked there
As for the rope factory I believe the first place burnt down in Southyard and the other was bombed out in the Plymouth blitz WWII in Northyard as was the sail loft , myself I only worked in Mauriceyard
The dry docks were built by the POW of the Napoleon wars from granite I believe most of the dockyard were built with them and its quite impressive what they done (poor guys) worth seeing, very much so on (NAVY DAYS) a very good show for all but bring earplugs for small children as cannons make a good noise ,, lol The RAF,Marines, Commandos ?Wrens make it a great day where you can also go in the war boats and submarines to visit while you can see where your ancestors worked