For sale is a Brown Sharp Tapered 5C Collet Chuck. It is B&s number 10 taper, as I guessed from looknig at dimensions. Please look at the pictures of caliper (not included) to decide if this chuck fits your application. The collet presently in the chuck is NOT included. I cannot guarantee any particular fit for any application.
In another auction, I have a KO Lee B995 grinder attachment that seens to have a B&S 11 taper. Check it out.