300tdi front seats

Have got a replacement set of seats for my Mreg 300tdi but on going to fit found that the seat runners ar wider apart on the replacement set and will not fit the original base. The bases that I have got are bolted to the floor and belive are the same as the 200tdi. Dose any body have a simple solution for fitting the replacement seats to the existing bases.

Piece of plate, drill all the required holes, 4 for old size, 4 for new. Bolt it up