So as not to make the mistake of setting the seat-frame up and discovering it doesn't fit the space frame, the thing to do now is to fix the lateral seat supports to the seat prior to fixing them to the space-frame itself.
To do this we begin with a broad measure of how far apart the conduit clips are going to be, and I've settled here on 130mm between centres. The reason I work to centres is that we can then set the clips on the seat supports and mark the drill-holes with a centre-punch... something that like me you won't have used since metalworking class.
