944 Turbo - Sill Check

[RGG]

The car's a 944 Turbo 1986.

I took it to 86K and then dry stored it during 2001 where it has stayed since.

Is there a decent test / check I can do to get a good idea of the sill integrity?

I have done an amateur knock test and I have also removed the sill vents and tried to look into the inners as well.

Overall, I think the car is in good condition bodywork wise.

Any help / advice would be greatly appreciated.

Thanks