I made some modifications to the rollers in the steamhead fitting, in order to accommodate the Rocna anchor. It would have worked with the standard rollers if I could accept that the anchor was resting in a small angle.
The forward roller was replaced with the HR 39-42F roller. This bow roller has a grove for the 8 mm chain, and guides the chain much better than the original roller.
The aft roller was replaced with a custom-made Delrin roller (diameter 50mm), installed a little bit lower and aft of the original roller.
This requires that you drill a new hole for the pin. In order to make it easier to drill, I used a 10 mm pin for the aft roller. (There is no load on that roller) Stainless is not easy to drill in. I suggest you buy 3-4 new drills and cutting paste. It is a matter of time. Do not go to fast as that destroys the drill.
Make sure the anchor rest on the roller before you start drilling.
For this job you need to bring the bowsprit to a workshop that works with stainless steel.
Our original bowsprit for the gennaker had to be shortened in order to avoid a conflict with the anchor. Also the fitting on the bowsprit with the pin had to be moved aft.
Finally I had to drill a new hole in the port side of the steamhead fitting, following the same procedure as described above.