Fallkniven make some great sharpening gear and the DC3t is a fantastic idea. Essentially you can attach it to any flat surface making it ideal for attaching to a sheath, tinder box, survival kit or anything else for that matter.
It is the same diamond whetstone that is on a DC3, but instead of the leather pouch, it is sold with a double coated pressure sensitive adhesive tape which allows you to fasten it on any flat spot, e g our zytel sheaths. The VHB 5925F tape is extremely strong and will harden permanently within 24 hrs. In size the D3t will fit the F1, S1, H1 and the A1 zytel sheath.
It is the same tape that they use to bond the stones together so you know it is MEGA sticky