@dhcod,
Assuming you only broke the plastic part, send an e-mail to VPI and see if they will sell you a replacement - just the plastic part. Its held to the threaded metal knob with just a snap-ring. This is the type of plier used to remove/replace the snap ring - Channellock 926 6-Inch Snap Ring Plier | Precision Circlip Retaining Ring Pliers | Includes 5 Pairs of Interchangeable Tips | Made in the USA - Snap Ring Pliers - Amazon.com If you search Amazon there are cheaper versions.
Assuming you only broke the plastic part, send an e-mail to VPI and see if they will sell you a replacement - just the plastic part. Its held to the threaded metal knob with just a snap-ring. This is the type of plier used to remove/replace the snap ring - Channellock 926 6-Inch Snap Ring Plier | Precision Circlip Retaining Ring Pliers | Includes 5 Pairs of Interchangeable Tips | Made in the USA - Snap Ring Pliers - Amazon.com If you search Amazon there are cheaper versions.