Fit Remove Repeat / Timewarp Tank

Whilst the electrician is making holes in the games room I'm doing some round-tuit-ing in the loft.  

Past electrical , fire alarm, roofing, plumbing works have left areas of the insulation is rather a mess with gaps and piles, and it's always been a pain to move around up there. Thus plan A is to put in a walkway for the most-travelled and most-awkward parts, meanwhile, implementing plan B to 'reset' the insulation - removing the carpet, newspapers and plastic sheets that past owners thought a Good Idea.

There's an implicit plan C in prepping for the plumber who is coming next week to replace the main cold water tank and install a second on the other side of the house to resolve problems when everyone decides to have a bath/shower/piddle at the same time.

Anyway, amid all this, I extracted this galvanized water tank in remarkable condition (less so inside).

Given that this is the second galvanized tank to be extracted - the other much bigger - makes me wonder whether there previously was a solution to the multiple users problem and that in around the 80's someone thought consolidating to one tank would be a Good Idea...

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Edit:
A quick googlerummage rather surprisingly pops up that the Bristol-based Redcliffe Crown Galvanized company is a late 19th Century affair - the partnership dissolved in 1881 though the trademark was brought and used by another company for a few years.

However.

The BSI Kitemark really only came into play in 1926 (though the idea predates that somewhat - 1903).

More googlerummaging needed.