i hav the power lead and speedo cable through the brake hole but connecters still exposed (looks a mess mind ) when it rains every thing works apart from speedo !!
Mine is mounted to the legshields, above where you've got your EGT guage. Seeing as the vapor has an EGT built in (I'd imagine... obv not got mine connected up), you could ditch that and put it there. All wires then go straight through a hole in the top of the toolbox.
Mine works in all weathers.
Pretty sure they're not waterproof, I think if yours in the picture you're going to have to notch the headset top slightly and put the connectors inside, it'll make a neat job of it, I mounted mine on my toolbox top and put the connectors inside:
Vehicle Wiring Products do good waterproof connectors in a selection of sizes.
Been using one for my tacho hanging just inside the legshields for years with no issue.
Their website isn't loading for me just now though...