Steve,
I found a "Bro-Tek" bolt-on thumb for my B21. The company website shows a picture of it mounted to a B21. It's on my wish list for now. Below is a recent communication I received from the seller. Good Luck.
I would like to first thank you, for your interest in our products.
Check out our web site
Bro-Tek: Tractor Add Ons you can directly download the installation manuals from the web site.Web site is still under construction, but same manual for the BX applies to the B21. Check out the attach photo.
These manuals should help answer most of your questions, if not, please feel free to email me.
I can sell the thumb direct to you with Pay-Pal for $390US (Standard Shipping & Handling is included in price, anywhere in the USA). Note: Standard delivery is 15 business days (3-4weeks) This deal can be ship Express delivery 5-8 business Days (1-2weeks) for an added $35US.Note: The Top-Link is not included for the Thumb (most people use the factory one) please add $35, for a new Top-Link. I have the Thumb is normally in stock & can have it ship the next day. I do have now a ripper tooth for the B21/BT751 & can sell you a combo deal for $720 S&H included. I can have these ready to be ship, by next week.Add $140 for the plow option on the Ripper.
If you decide to purchase, please reply to confirm your Telephone #, full delivery address (**Shipping is Via the post office, if there?s a PO Box # required, please indicate), tractor model #.
Once I?ve received your information, I will send you, a Pay-Pal request for the amount to your email address.
Pay-Pal will take you through the step by steps to create your account, should take 5 minutes to setup (easy to setup).
Most comments on Pay-Pal are: Paypal was easier than I thought
All the info is on the web, Pay-Pal is used all the time to buy/sell on eBay.
If there are any more questions, please ask away.
Thanks again,
Richard/
Bro-Tek@hotmail.com