Standard KH Seat base T-nut attachment

Does anybody have a picture of how the nuts fit in with the reinforcement plate on a standard KH seat base?

I’ve got an older style base with bolts instead of nuts which I’ve taken apart to have a go at reshaping the foam and possibly flattening the base to make a cheapskate’s Flatfish (I’d love a genuine one, but am struggling to justify the cost with my current situation - a quick test suggests it’s possible to bend the base by immersing in boiling water). I’d really like to change the front handle fittings to use nuts rather than bolts whilst I’m at it so I can use a KH T-bar with it.

The base has indents which would take standard nuts, but it wouldn’t be possible to use the reinforcement plate if I fitted nuts in those, and I suspect that would be a bad idea when using a T-bar! So just wondering how it’s done in a current base.

Have you considered maple plywood or an old skateboard deck? I’m not sure that a flattened one will stay that way after you start pulling on it. I’m tempted to try it but don’t have a seat to sacrifice- yet.