Ehhh, if it were me I think I'd risk it.
Looks like the early models had a crossbar that the later ones didn't have
I know the bumpers were different on 05-06 Foremans and 07-11 Foremans, but they were interchangeable. The difference was tube on the 05-06 vs I beam on the 07-11 mounting points, but the bumpers were completely interchangeable.
Carrier (front rack) is the same on the 07-13 420's, so that tells you the top mounting points are in the same place.
Winch plates are the same 07-13 so that tells you the mounting points on the front of the frame are the same.
That leaves the bottom mounting holes, and I highly doubt they are in a different place.
No guarantees, but it just wouldn't really make sense for Honda to change the frame THAT much on the same generation of machine, simply for different bumper mounting points. The 07-08 Frames ARE different than the 09-13 in the back, because the later frames added an additional rear end mounting point for the IRS rear cage on the AT's. The footshift and ES swingarm mounting points stayed in the same place.
If you do gamble and order the cheaper one, let us know how it works!