That's "4' questions...at least! "BUT"...Here's the deal:
*#14 or #15, CDT's catalog @ $15.00 "less" than the full, exposed tang versions...and leather is the standard handle. Black micarta or other material is chargeable.
*#14's & #15's, when ordered with a single hilt receive thumb notches automatically @ no additional charge.
*Combat Companions, whether CDT or full tang "can" have thumb notches installed..."BUT"...that option "is" chargeable @ $35.00.
*BCP option is chargeable @ $35.00
Hope this helps,
Stay Sharp, Capt. Chris