it's a pretty cheap and nasty website isn't it? some areas still under construction too. i can only assume that they are a brand new team
Mayfly - any of their Strikemasters ones that DT's done airtests on? he's Mr. JP after all - any idea who they are?
edit - airliners.net have only two pictures of G-MXPH (the a/c shown on Team Viper's own website) - seems the a/c itself is based at Northolt, and one picture says this...

G-MXPH / 311 (cn EEP/JP/1931) This privately-owned Strikemaster is one of 16 which were delivered to the R Singapore AF in 1970, serving till 1983. It first arrived back in the UK in 1994 as G-SARK and is seen here resplendent in its original livery featuring the first-generation RSAF roundel which is the same as that used by Turkey and Peru
that's the only Strikemaster i can find reference to based at Northolt
sm