Help with a 185 Hydro

I have a 185 Hydro and every place I look says that the biggest deck it came with is 46", but mine seems to be 48". Has three blades that are 16" long each and measuring the deck seems to put the cutting area at 48" unless I am measuring it wrong.

I can't put the mower on a 48" wide landscape trailer as the mower deck is to wide and hits the metal sides of the trailer.

Any thoughts? could somebody have put a different deck on it?