Different 175 Dual Twin Seats?

[paul25g]

I've noticed different types of seats on photos of 175 Dual Twins that I've seen.  Some (like mine) have a small hump molded into the seat right behind where the rider sits.....others are flat the whole length of the seat.  Does anyone know the difference?  Was one type used earlier on and then it was switched to the other?  I was thinking about using a replacement cover from Pit Replica but see it is the version that is flat the whole length of the seat.

Thanks!

Paul

[disc_valve]

I believe that the humped seat was used on very early Dual Twins. I'm not sure when they changed over, but there's a sporting chance that the seat frame would be the same on both types of seat.

The later Dual Twins and Hurricane Scramblers both used the same seat frame and foam, but the covers were differently styled

Graham