Slipway mounted on rails

I have designed this slip to comfortably accomodate a beam of scale 24ft and max length of 60ft. The framework after rivetting detail completed was sprayed with grey primer. I then went to my (salvaged) wood supply and chose this piece of conti-board and cut it down to 33ins x 16ins. Next job was to fix the rails onto the board.  These brass 'G' scale rails were also salvaged (from my bosses garden). They came with chairs  and after one rail was laid as straight as possible, the remainder were laid at 6.5mm gauge for the centre pair with the outriggers spaced out at 140mm from the nearest of the centre pair. The base board was then inclined to 7 degrees.