Problems in extruding according to surface normals.

Hello,

I was fortunate enough to receive some fantastic advice in response to my last question - and the solution of that (of course) revealed another roadblock that I hope someone can shed some light on.

I have a fairly simple surface that I'd like to extrude:

A simple extrude using the world Z as a normal works, but because of the vector used, the extrude doesn't follow the normal of each face - which we see in the direction (always down) of the holes punched in the surface:

I had thought that the solution would be to use an Eval node to get the normal for each face on the Planar, and then feed that into the extrude. However, that lead to two unexpected problems.

First, some faces extruded in one direction, and some extruded in the opposite direction:

Secondly, the faces became disconnected from each other at the end of the extrude:

Any advice on these two problems - most likely due to my inexperience - would be much appreciated.

Thanks again,

Elliot