@JTT,
JTT wrote:
Google Exact phrase search for "was blew up", UK region only yielded
About 1,230 results, McTag, which is not a small number for such a phrase.
I tried to duplicate that and got 41 results, including "Yeh but i heard it was blew up by the america goverment. " (a board abut 9/11), and "So that means when he was blew up as it were he wouldn't feel the explotion he would feel the dalek." (a Torchwood (Doctor Who) forum)
Those seem more like errors than variant usages.
I searched the exact phrase "was blew up" and restricted the search to .uk domains.
I would hesitate to draw many conclusions about spoken UK regional dialect usage from a Google search of written material on the web. Having said that I have a feeling that it might possibly be a (becoming obsolete) spoken variant in Northern Ireland.