In my wanderings I saw this valve seat grinder set, it has the special pilots for model A and flathead V8 ---I have no interest in it( because it is something I have) or no connection to the seller, it is quite old, "from the era", probably pre WWII, the stones are still made, looks to be complete enough to do most 30s era cars with what is there. I used a set like this to do my first valve seats.
http://www.ebay.com/itm/BLACK-AND-DE...3e7ee4&vxp=mtr