Solved!
Credit and thanks to Llew for the idea
Here's what I did:
-Using a standard shield as my 'template' I changed the mesh and stats, using Morgh's tools. I also gave it the capability of 'carry_bowcase_left'
The real interesting stuff
In openBRF, take your buckler mesh and duplicate it. Move the duplicate along the Z axis, about -0.5000 worked for this particular model. I also rotated it a bit, just by trial and error. For this bucker I rotated it as follows:
X 20 degrees
Z 15 degrees
I also moved it down on the y axis a bit. I also imported the strong bow case, and used it as a reference.
Go back to your original mesh, and copy and paste frame. Change your new frame 1 time to 0. On your duplicate, copy the frame and paste it in your original, after frame 1. time for frame 2 doesn't seem to matter whether it is 10 (like the bowcase) or 300(like a shield with a strap).
My item_kinds txt entry:
itm_new_item1 Buckler Buckler 1 talak_buckler 0 8454151 2952790016 50 167772194 2.00000 100 0 40 0 0 100 100 0 40 0 0 0
0
0
(buckler from Unique Armory OSP)
The inventory pick is still a bit wierd, but maybe a new game will fix that...
So, case closed....