Since you brought it up.... to me, the Corbin feels shorter than the OEM seat, more than the claimed .25. Maybe Corbin is measuring at the point where the seat meets up with the gas tank. I bet if you measure from the rear of the driver seat to the ground, on both seat, you'll gain a few inches.
More importantly the Corbin is firmer, flatter and it doesn't have the forward slope the OEM has.
I would try to "test sit" on a Corbin before you buy. Some like the Corbin sone don't. I love mine!
Check out the "For Sale" section, there are always Corbin seats for sale.
Sorry to get off thread..... check the "For Sale" section for a used backrest.
There you go..... back on track!