I'm really surprised that you've had so much trouble with pens going into the Compagna pen loop. I have experienced the opposite - all the Compagnas I've owned have had roomy, elasticized pen loops that held large pens, including my 5 cartridge Uni Style Fit Meister. In fact, I'd say I had the opposite problem with one Compagna, where the leather got so stretched out, the loop became too big for certain pens, which would just fall right through. However I do have issues with all the pens with rubber grip material on them - like my beloved Coleto. :( The rubber grip material makes it impossible to slide the pen in & out.
Can you tell me where you got the numbered clips that you use on your monthly page? I've searched google and etsy and can't find anything other than the midori clips that I worry would cut into the paper.