Steel housings on all Ruger NM revolvers

OK...need some help from the RF masses here.
Just checked with a dealer who offers quite a few Ruger single action models and found that Ruger switched to a steel housing on the rest of their New Model SA's (yes, also the aluminum grip framed guns) sometime before March 5, 2012!!! That's going on 3 years now!!!

So what I have so far is not much...

NM Single-Six 265-46805 steel housing

NM Single-Six 10-shot 810-08906 steel housing

So I also need info on the blued Blackhawks...which would have changed to a blued steel housing before about 38-17000 for the .357 Blackhawk and before about 48-54000 for the .41 and .45 Blackhawk models.

The New Bearcat is another matter. I suspect Ruger probably changed to a blued steel housing on the blue model about the time the stainless Shopkeeper came out, but need info on that as well.

And of course, need to have some idea as to highest known sn's for the aluminum housing on all Single-Six models as well as the .357, .41 and .45 Blackhawks.
When you supply info, a born-on-date will also help immensely if you still have the fired cartridge case envelope.
Chet15

PM'ing the info on my NM Blackhawk

Will these be of both the "large hole" and "small hole" varieties?

Update...BN455X #48-46090 with a Born-on-date of September 28, 2010 has a steel housing!
I'm surprised this is something that slipped by everybody for so long!
Now I'm wondering if the change didn't occur at the same time the Vaquero went from aluminum to steel. Will need to check my notes on that.
Chet15

Ale-8(1) said:

Will these be of both the "large hole" and "small hole" varieties?

Click to expand...

I know on the old models the Blackhawks and Single-Sixes had two different size ejector screws, but I'm not sure if that continued with two different sizes on the NM Blackhawk and NM Single-Six.
But yes, if so, everything is steel now.
Chet15