Does anyone have an extra shift knob for a 1921 490 they would be willing to sell.

This one is listed on ebay at the moment, you will have to check thread sizes with the seller though.
http://www.ebay.com/itm/1940-50s-FO..._Car_Truck_Parts_Accessories&vxp=mtr

I am planning to visit a friend on Thursday. May be he could have one fitted for 1916-22 for sale. The price and postage cannot be that bad.

I will wait to hear from you once you return from your friends. Until then I will talk to the ebay-er to see about his. Thanks to both of you for getting back with me.

By the way, If he has a cap for the oil fill tube I am in need of one of those also.

Sending you a PM today.