My MV6 has no rear spoiler, wood interior trim and an Elite style front bumper. It has sports seats and lowered suspension though, and every other part of the spec. is right for an MV6. History is clean and I've done a reasonable amount of digging around on it and no reason to suspect anything is not original (not until I drove it anyway
).
When I had to change the front bumper due to an embedded motorbike, the spec was checked against the VIN and confirmed that it left the factory with an Elite style bumper (good job IMO cos I don't like the facelift MV6 one).
It seems that the spec did vary a bit. The owner history of my car does suggest it was pre-reg by Vauxhall as it has them briefly as 1st owner. Maybe they didn't fit the lower volume MV6 panels to such vehicles to cut costs?
Anyway, it doesn't appear to be unusual, so I don't think you have anything to worry about.
Kevin