Paul - Ah! Thanks I thought I understood what the issues were. The turret came with the lathe and carbide insert holders as well. My experience using carbide is with a table saw and wood. I was very unhappy with the finish results of carbide on cold rolled shaft steel, and I chipped a lot of inserts.
From your description I could use HSS whit the 10 deg relief(s) and a 10 deg slope on the top, once shimmed to center it could be resharpened and should be aligned to center when reinstalled. Increasing the backrake would help it 'peal' the metal?