Weather station scaffold tube pole adaptor

Currently, I have my weatherstation mounted on a 1 1/4" aerial pole fixed to the gable end of the house. I have always had erratic rainfall measurement and discovered that it is due to the aluminium pole, which is around 6Ft long, whipping around in the high winds. This is especially true with the Weatherflow's Tempest, which has a haptic rain sensor which appears to be exceptionally sensitive to vibration.
Consequently, I've decided to mount the weather station onto a scaffold tube mast, clear of the house. The only issue was how to affix the station to the pole without it looking like it had been carried out by Mr H Robinson and Co.
So I've designed this adaptor. It is designed to fit inside the end of the scaffold tube and covers the top edge, whilst having a circular (Annular) slot designed to accept a 1 1/4" aluminium or stainless steel tube which is the usual mounting pole diameter for these weather stations. It looks much neater that tube clamping the mounting pole to the side of the scaffold tube and provides a strong and rigid joint.
I've designed a drilling jig which slips over the scaffold tube to ensure the bolt holes are drilled in the scaffold tube aligned with the corresponding securing holes and nuts in the adaptor. It's the grey bit in the prototype photo with the red / grey parts. The adaptor is designed to accept a standard galvanised steel scaffold tube, 48.3mm external diameter, max wall thickness of 4mm.
You will need two M5 nuts and a pair of M5 screws, either 30mm long if using the internal mounted nuts or 60mm long if passing right through the scaffold tube.