/\ correcto, VP with IRS are the only one to have a different offset. Either use spacers/longer studs (i have this for my grange wheels) or do the simple fix of changing to VR onwards hubs (which is what will be on the cards when i can be bothered)
the VT to VZ wheels sit about 15mm closer then the VP IRS, the VP IRS off set is 28p and the VT onwards is somewhere around 40p-45p im not 100% sure, all depends on tire width to weather there 245's or 235's.