\Dunno if anyones tried shiftig the stock steel hangers to the rear of the mounting plates . Tecnically the tourque will twist them , as you land at the bottom of Bray Hill at 150 mph ,
and lock the rear brake . So if your 20 stone, dont try it .
https://www.google.com/url?sa=i&url=https://www.obsoletebikeparts.com/a-57987285/frame-parts/norton-p11-a-g15cs-pair-of-folding-footrests-inc-029859/&psig=AOvVaw0lcTzWWNNWX7FekcbRoQks&ust=1682396446640000&source=images&cd=vfe&ved=0CA8QjhxqFwoTCNi5sKbVwf4CFQAAAAAdAAAAABAa
NoW , a bit of butchert , Ahem E N G I N E E R I N G
On these , being ' in house ' youd have ' period ' fittings , and being lighter , they wouldnt slow you down .
As in you can see theyre not as beefy , Fist trick'd be using the bits on the end on new similar tube , and plates to fit hangers - 3 bolt fit.
Or just find the pegs & bolts . The rests ; custom ' or school metalshop stuff , ifin you know metal bonding .
https://www.google.com/url?sa=i&url=https://www.ebay.com/itm/234784399692&psig=AOvVaw0SXb29Y_6TKY0yyPd2tPIT&ust=1682397216109000&source=images&cd=vfe&ved=0CA8QjhxqFwoTCJjPrJXYwf4CFQAAAAAdAAAAABAE
OR

Something with a vaugue resemblance to this , at the three bolt fitting , With bits like THESE welded / bolted through from aft , if the plates thick ,
Whack all the bit on the left off , and weld the big diameter bit to 1/4 steel plate ,drop em in at your local galvaniser .
Dunno if these blokes wouldnt knock out a set for you ;
https://sjmotorcycleengineering.com/collections/footrests
skunks if they wouldnt . See the bolts in through the back side , on these . So as is - countersunk somewhere to clear a H.T. Allen Head Blot .
Technically , a say 2 in vertical x 1 1/4 tempered plate or washer behind it , It'd bolt STRAIGHT TO the Std. Plates- drilled .
A thing with a shafty bit like that , will take rotateing bits , like brake levers & the other one too. On the other side .