Skud63

I have a pre 2023 M2 3 gun 12 gauge with a performance shop 7 shell magazine that I which to covert to a legal Florida Waterfowl shotgun I am planning on getting a 28 in barrel but can't seem to find a 5 shell limiter plug Florida has 3 shell total in firearm so 2 in magazine 1 in chamber what size and where can I find a standard magazine and spring with a plug limiting it to 2 shell capacity Thank you in advance Mike