Thanks for posting the pics for me!!
For those interested: alumin(i)um plate is 40mm x 80mm x 3mm thick (1/8")
Hole pattern to match handlebar clamp is 27mm x 40mm, holes ~5.5 mm dia.
Bolts to replace originals are M5 x 40 socket head cap screws.
Spacers between handlebar clamp and alu plate are 20mm long (3/4"), drilled to clear M5 thread.
Bottle cage is std. from a previous bike, on 1/2" spacers to clear bolt heads. Most cages will fit alu plate.
Extra holes are from 1st try. I plan to spray pieces black to match handlebars etc.