For Mexican IPSC and NRA/Action courses, the little clippy-type holsters are generally discouraged as they're hard to get here, expensive, and not something you'd probably wear as a rural (Rurale) policeman out in the back-boonies. Some guys use them, but you can see the squinty-eyed looks they get from the mustachioed, leather-tough guys who show up to the matches with their Heavy Dutys in a Jordan-type holster with a River Belt. Since shooting down here is literally taking a step-back in time anyway, I'd rather not have the locals looking at me too askance. (This always gets thrown out the window when another Canadian friend and an American friend and I get to drinking and deciding we should show up to the next match dressed as "The Three Amigos". But that's the booze talking.)
My Mexican competition holster is a Milt Sparks Hackathorn Special made for revolvers. Quite pricey and with a long waiting time, it does the job nicely. Mine is cut for the crossdraw/front hip-bone rake and works nicely. It works perfectly fine with the 627 and could be made to fit precisely if desired.
Another popular holster down here is the Galco Dual Position Phoenix. The guys take the holster to this little guy a few blocks over just across the street from a friend's house who has a little shoe-repair leather shop. They get the guy to cut off completely the thumb-snap release (the DPP has a tension screw that is perfectly serviceable, and the holster
covers the trigger guard) on both sides, refinishes the leather so it looks like it came that way, and then continues the thread-stitching over the cut part so that you really cannot tell it didn't come that way from Galco.
Those are cool looking holsters, no I do not have a photo of one but I'll get one the next time I have a camera at the range as it's probably the most common "Mexican IPSC" revolver holster in all frame sizes. I'm getting one myself as the DPP allows you to choose between cross-draw or standard draw and I feel the Milt Sparks holster would be greatly improved with a similar mounting system but I can't change that now.
Finally, in the Blue Press, Dillon has a holster -- more a concealment or daily carry holster than a competition holster -- that looks like it would nicely fit the 627 as they say it's for the 5-inch N-frame slab-sided barrel. I'm thinking of one of those eventually. It would certainly fit in nicely with the type of holsters the local range-riders like to see one wearing at the matches. These are the type of guys that have been "taking back" towns South of here lately, and so their opinion does matter to me as I think a lot of them.