Welcome to the Forum!
As my friend Robb has pointed out, "it depends."
There are very few factory installed brass grip frames that will "letter" as having been shipped that way. Example;
The known serial number range for the factory shipped brassies is 40-18080 to 40-22214. The known quantities; BKH-41B=50 (That's only 50 guns with the short barrel.) and for the BKH-42B=160 (the longer barreled ones.)
So the gun you mentioned falls into the range of the "possible" ones.
A formal request to Ruger for a letter on how the gun was shipped only costs $10. That would be CHEAP if it letters.
Factory brassies are rare & expensive when they letter.
Next, add in the condition of the gun, and if it has the box, or, especially the brown bookwrap shipper. If the bookwrap shipper has the BKH-41B or BKH-42B on the end, then it's very likely it shipped as such.
All that said, it's more likely the gun had the brass grip frame added after the fact.
And as Robb has said, it's value is in the sum of the parts.
If it's a Ruger brass g/f, then the value of the g/f itself is around the $300 mark. If it's an aftermarket g/f, less. Usually around $150. Next a gun w/o a g/f at all in 41 mag would be in the $300-$400 range if in very good condition.
So, if it letters,,, it's worth a lot.
If it doesn't letter, then it can be worth as low as $450 with an aftermarket g/f to as high as $700 if the g/f is a Ruger one. This is assuming it's in very good condition.
A Ruger grip frame is the same shape as a Super Blackhawk g/f with the square back dragoon type trigger guard. If you pull off the grips, then you should find markings in the casting of; MR-3DB.
I hope this helps a bit more.