Howdy moose21. Welcome to the forum.
I have an old 4566 that I never had a holster for until recently. Someone was selling a leather Safariland paddle holster for it cheap, so I grabbed it. As you know, the gun is a heavy piece when loaded, but this holster does the trick. It is an OTW style with a thumb break, so you would have to get creative with your clothing to carry it concealed. If I was ever to consider carrying this gun, it would be in colder weather where I could wear an oversized sweatshirt or sweater to cover it up.
There are many other IWB holsters made for this gun as well, but I find the gun too wide for IWB carry.
WG840