Bobcat 324 Thumb

I can see the value of adding a thumb to the 324, but don't know how the genuine Bobcat thumb is attached to the dipper.

Would anyone have any pictures and specifics of their thumb, or at least tell me how they are attached?

Obviously I could just weld something on, but I try to keep everything as close as the original manufacturer's designs and intent where I can.

I have some other attachments I will fabricate for specific jobs waiting, so will add this to the list when I can.

Thanks

Bobcat 324 Thumb