This is a rare unique item - I'm not totally sure about it as I'm no detective - but on family history a very well established Plumbers in Rochdale Ezra Travis & Son (I think - it may not have been Ezra!) closed in the 1960's and my late Father's friend bought the premises and this glass domed example of "a Six way (branches) piece made of sheet lead" was in the office and left behind it was going to be thrown out and my Father brought it home and put it in his den. With it is a foolscap sheet of old blue paper (see photo) which has the heading "a Six way (branches) piece made of sheet lead" This goes on to tell in great detail how this six way junction was achieved. This must have been made during the time all plumbers used lead - before plastic - and it was a real skill.

It also says "Made at Home in spare time" and amongst items used to create it a "coal hammer" (!)
It also says it was shown to Capt E. Edwards R.N. Eng Overseer (this suggests Royal Navy could it have been an apprentice piece?), and two other RN names and ends "who complimented me and advised to being sent to Exhibition (at the) Technical Institute"