There was a reported VERY FEW(3 maybe 4) "cleanup" 41 mag Blackhawks produced, but likely unverifiable by the factory due to the rarity of them. No known serial numbers of any have ever been reported to the RENE. So, don't hold your breath trying to find one.
As such, the normal factory production was limited to the 6-1/2" guns.
Now, there was a Bisley variation in 7-1/2" offered and when found usually sell for a premium.
But, a 6-1/2" barreled 41 mag is just fine for deer hunting. I own a few of the OM 41's in that length, & I'd NEVER feel under-gunned with them. I bet the 41 with a 6-1/2" bbl will outdo most folks who can pick them up to shoot. If you desire a 41 mag Blackhawk, get one & begin to enjoy. Fear not, the deer will feel all the fear for you.