Really nice Hydrostatic fuze in the first 4 pics. I have a very similar earlier MOD one and was told it was for a depth charge?
Jason
Some information on the VT fuzes from the set pictures uploaded by US-Subs, 2nd of April, 2014 http://www.bocn.co.uk/vbforum/attachment.php?attachmentid=90030&d=1396428525 & http://www.bocn.co.uk/vbforum/attachment.php?attachmentid=90036&d=1396428540
Not certain, as some of the mines also used similar devices for arming, etc., like the air dropped mine photo number 89800 on the previous page, near the top. For US EOD the Navy was always very territorial, they guarded the info and tasks related to all UW stuff very jealously, even all the way back to WWII stuff. In EOD school we land dwellers were begrudgingly given 1/2 day of UW ordnance, not even a basic recognition course.