Extending Seat Brackets

My goal is to create an additional 2"-3" of leg room in the driver's seat. Due to the shape of the floor, it looks like relocating the entire bracket rearward wouldn't be fun. Would the best option be to actually shift the seats back on the brackets? Is there enough metal frame to do this or would I need to sandwich another metal strip in there to bolt it to? Aftermarket - I couldn't find a ready-made kit but am pretty new to XJs. Is there something out there?

I haven't even pulled the seat yet so pardon my ignorance if the solution is pretty obvious. Hopefully I'll take a stab at it this week.

Bump.

make a bracket that mounts to the stock bracket and then mount the seat further back?

I welded 4 .25" thick steel plates on the bottom of the existing frame and drilled holes about 2 inches forward. Been running them for probably 5 years.