seat base differences on A65

[DAVE BRADY]

Hi,

What are the differences in the mounting of the earlier 'humpless' seat and the later 'humped' one. 
For passenger comfort I would like a 'humpless' seat on my '69 A65.
I had a seat done without the upholstered hump but the base still has the hump in it so will an earlier seat fit?

Dave.