https://www.supersproxusa.com/products.php?cat=1114400Yes, Supersprox has the rear sprocket altough not in stock, they are made to order.
they also have the front sprocket but not at the moment they are comming in again in 90 days or so.
from the received mail:
Part no for rear sprocket is RST-7091. This part no. is not a stocking item. We can produce only on order.
There are 2 different ways of production. Cost of the sprocket is 69.95EUR in both cases.
Machining before anodising takes 12 weeks.
Machining after anodising takes max 4 weeks but in the places after machining will be no anodising.
Front sprocket is CST-1439:14 however this part no is not in stock. ETA is 90+ days.
I also found that more companies offer sprocket for our after market marchesini wheels
sprocket dimensions are 10.5mm for the 5 bolt holes at STC.100mm
hole diameter in the middle is 76mm.