I can't directly answer your question, but the bevel lines where well marked (CNC scribe lines) on both sets of forms that I bought from CLC (Mystery and Yukon).  You should be able to tell by comparing the forms with the plans.  If not, I'd call CLC and ask.  In any event, the exact length of the boat +/- an couple issues won't really matter unless you are planning to race it.  

I am not sure what you are planning, but carving a solid internal stem is really easy.  I suggest watching Nisk Schade's video demonstrating that on a Bootlegger Sport.

First picture shows Mystery forms as delivered except that I highlighted the bevel lines with a red magic marker.  Second shows completed solid internal stem. 

Hi JP, 

i have built the night heron and its a bit confusing....but the form needs to be cut back to accomodate an internal/beveled stem.

if i recall, they may have included a piece in the kit that represents the beveled stem.  you need to place that piece over the stem and trace the bevel line and then cut that off.  then add back a proper piece of spuce or other wood.that can serve as an internal stem.   the greenboard/particle that they now ship for forms/stems is not suitable material to actually include in the boats construction.

i am looking to see if i have a good picture of that from my construction to share with you.

howard

looks like mark gave a good illustration.  my sense is depending on the vintage of the kit, they may have scribed it for you (newer kits/designs)  in the older kits/designs, you had to scribe it yourself.

but

   Thanks for quick replies.  Makes sense now.  I will have to cut the end form to attach an internal stem.  Easy enough and I have bendable wood to laminate for a stem.  Also it turns out the bottom point of the 1,2,16 and 17 forms, where they attach to the end forms mark where I need to cut.

Thanks and stay safe,

Jeff

   Howard, on further inspection of the rest of the kit box, I found the pieces of particle board based, internal stem templates you're talking about.  

Since you have templates, it will be much easier and quicker to carve the inner stems then laminating them.  Watch this video by Nick: https://youtu.be/hAh-qPYf0rk