Besides the holster, have you considered what gun belt you're going to hang it on? that M-29 has some pretty serious weight on it. Anythingother than a dedicated gun belt will make your life miserable.
For me a full flap holster is a pain in the keester to draw from. They look good, but without a lot of practice they're not very efficient.
I recommend going to a gunstore and looking at a varitety of the holsters available, and try them out with either your pistol (if they'll allow it), or one of their pistols.
My ultimate preference is the
1791 holster brand. @
Home | 1791 Gunleather e-Shop Holsters, Gunbelts, Rifle Sling, Magazine
For my N-frame revolvers I prefer a simple thumb strap holster
Holsters are so hard to get "right", that many of us have multiple holsters for any given carry gun. What I think You might like may be so far from reality that what we like can only be simple suggestions.
I have 3 very large totes full of holsters, for many of the guns I own. And most of them are in the totes because they never lived up to my expectations.
This photo is about 25% for the holsters I have. Most of these are for revolvers. My absolute favorite outfit is the black Lawrence gun belt and holster, at the far right top in the photo.
Blackcloud3 here on the forum gifted it to me.