For a pair??
If they fit mine then I will sell someone my custome frames!! They are the dogs bollacks (should be for the price) as these will save me weight!!
for a pair, yes
take note though that even with the seat mounted on the highest sidemount point, the seating position will be lower than standard. your custom frames act as a raising spacer as well
I also found a workshop who can do custom frames here but they'll cost around 200 pounds per seat. I'm not convinced about the strength and safety of a custom welding/mounting though
didn't see a Sparco/renaulsport sidemounts combo yet, but Cobras fit well