2 1/2 model 66 holster.

[Black Knight]

Another vote for the Bianchi model 5BH. I carried my 2 1/2" 66 in one until my wife claimed the 66 for her gun. She now has the left hand version for the 66.

 

[georgek472]

If you don't require a thumb snap retention then Azula is a great value. I wore one with my 3" M629 for a year. My brother has that holster now and it's certainly high quality leather and stitching!

I have one...This holster is not lined.. Hard on blue #19's

 

[Texas Star]

If you don't require a thumb snap retention then Azula is a great value. I wore one with my 3" M629 for a year. My brother has that holster now and it's certainly high quality leather and stitching!

I'll go with this or the Bianchi Shadow. I carried a four-inch M-64 with a Shadow under a short jacket and no one ever saw it.

Have also used Bianchi 5BHL and Safariland's old M-29, now basically copied as El Paso's Model 2.

All were good, but the Shadow probably works best for real concealment. The Azula is probably on par, but has no retention strap.