I have a call in for RickT to call me back in reference to the forum policy about these links. I have others who have legitimate questions about it. The reason for the rule is because of all the cross-forum bickering and bad-mouthing (often by banned members).
With regards to your question: Model #19's come 4 1/2" and 5". Sheaths are, most-often stamped: 19-4 and 19-5, eliminating the "halves" if you will. Hope this helps.
Stay Sharp, Capt. Chris