Bolster Seat Dimensions?

[Oberon]

I'm modifying my non-bolster seat into a flip-up bolster seat using OEM brackets purchased from Bakes. I'm going to cut the original seat bottom in two pieces but am not sure what dimensions to use so I'm asking for the help of someone who has access to a seat with a bolster. My seat is about 18" deal and based on pictures I've seen I should cut it in two 9" halves and round the corners appropriately. Is this correct?

If you can answer any of the following questions I would appreciate it.

How deep is your bolster?

How deep is your fixed seat cushion?

How thick is the padding on your bolster?

How thick is the padding on your fixed seat cushion?

How is your bolster attached? Machine screws or lag bolts?

[Oberon]

Well I figured out how to attach the cushion; machine screws into t-nuts. The stainless hardware alone costs about $50.

I'm still looking for dimensions if someone cares to take a tape measure put to their boat.