the Plessy site has gone through several owners since back in the day. It might be called Plessy now but its nothing to do with the old Plessy (apart from being run by ex-original Plessy people) It now makes LED lighting, ad its a leader in it.
The hot rocks was a good trip, very much before its time. Goonhilly was really cool had a special behind the scenes tour with an old BT lag
There's been a really good documentary about Devonport dockyard on Quest (I think) its still bleedy massive!
And as for the brewery, well that's still there but the college has moved its no longer at Palace Rd I think its over at John Key house the old EEC HQ. The brewery was great the smell of it wafting over campus of a morning.