My wife has a set of 28 and 410 tubes for her Pre-Type 1 20 gauge Citori. The tubes are easy to install and remove. So that is not an issue.
Briley tubes are good and will cost a fair bit. They can and will do almost anything that your need. Are you going for screw in chokes or a fixed choke?
Me? I would shoot it as is and enjoy the experience.
Mike
Thank you for the info and advice. I do not mind paying $750 for the assurance and peace of mind. By nature I am control freak and tend to over think everything. I want to enjoy the gun, be careful with it but, if an accident were to happen and the muzzle end was struck into something inadvertently, that the tubes would provide an extra back bone for the original barrels. Thanks again for the help.