Thank you Proud Kraut, Manny, Ronnie, Billrob68, patches, and sundance for your great support, and humour, towards this build. Much appreciated.
As I marked, with a pencil, the centre of a cross beam, for a reference to align the shorter arms, I noticed that I could use the pencil to mark bolt heads. Later, I will mark all the joints this way.
Have completed the bridge framework. Minder used to be a tight-rope walker. Here he is, showing-off on centre stage.
Added central girders, with braces (matchsticks), to support the railway sleepers (to be added).