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Sorry, I do not have any plans I'm afraid, I just built it up as I went along to fit the space I needed (basically enough height for most and a little post holiday 'girth'). The drawer runners were described as heavy duty and they were certainly heavy. It's crucial to get them perectly vertical or else when the four legs are connected together, the whole thing will lock up when you try to move it. My runners are those which have a soft closing action to the last inch or so the section needs to be lightly pressed home. I first fixed the small edge of the runners to some 1" square wood, then screwed them to the fixed uprights. Finally I added cross bracing, a peice of ply about 4" deep front to back to keep the whole thing square and the tops for the track. I've yet to source some other weights - at the moment I've about 3lb each side and that will increase slightly as I add scenery. I secured the rope to the bottom of the moving frame and used eyelets not pulleys becuase I wanted a little friction.
You mention Multi layer - do you mean it joins two or more trackbeds at different heights? If so yes, threre are two layers in my version, you can see the second one in the 'lowered' photo. If it helps I can take a few more photos from different angles to help make up for the lack of plans.