The straps aren't original I think. Mine had quite flimsy plastic coated steel strips which had almost rusted through when I put new ones on. I was about 10 miles from dumping the lot on the road. The galvanised ones in the pics above are much more substantial though incredibly wonky.
It leads to another point regarding the Moonraker. Mine had a lot of the metal parts coated in plastic which went brittle and cracked off. I cleaned various bits and painted them instead. Westfalia thankfully didn't resort to this AFAIK.
This is correct. The original straps weren't perforated like that. I have installed a normally closed solenoid valve on mine so I can dump the water with the push of a button vs using the rubbish plastic tap