I pulled the trigger on Monday and got one HC-P, very nice fit and finish for a $300 shotgun, very light and quick. It will be used for 3 gun comps in He Man division so will need to add a few things. So far I've found the following:
1) Benelli choke tubes fit from my M1 (Mobilchoke?) and M2 (Crio) - Ended up using a Light Modified from Carlson just because it patterned well with all shot loads and slugs.
2) Mag tube end caps - Benelli M1/M2 - DOESN'T FIT. Remington 1100/Versamax - DOESN'T FIT. I bet a Benelli Nova pattern would work but don't have one handy.
Other things to try later - perhaps changing out the stock to a Benelli M1 tactical since it is more robust (weights twice as much as the one that came with this CZ 612), modify/cut the forearm shorter since it is too long and in the way during weak hand reloading, open up the loading port similar to my M1 and M2 (probably not until I get a few boxes through since this last mod would void the warranty
***Edit to Update*** Benelli Nova extension tube nut from Nordic Component worked except it bottomed out 1/8" too soon. I need to add a shim plate. With the Nordic +4 tube set, I can get 9 rds in the tube and the tube end sticks out 4" beyond the barrel which is not an issue, all my other shotguns set up for competition are similar, 3-4" beyond the muzzle.