Finishing open grained wood

I'd like some advice please. I made a pen with panga panga/partridge wood. Difficult to work with, very splintery but a lovely grain. However, it has a very open grain which I tried filling with thick CA but that didn't really work and the finish is not smooth. How would you finish it? Previously I've made boxes with it and used wood grain filler (not wood filler), then a cabinet scraper and finally French polish. I'm unsure about pens, though.