these might be worth a look if making tools - cheap enough if making an order up with a cutter for free delivery. Pity there's no round one. Wealden stuff is always good.
https://www.wealdentool.com/acatalog/Online_Catalogue_V_Groove_swop_tip__898.html#aT8225_2d1_2f2
https://www.wealdentool.com/acatalog/Online_Catalogue_V_Groove_swop_tip__898.html#aT8225_2d1_2f2