Rockwell T221/SM465; Rare T-case?

['68OrangeSunshine]

I got this transfer case at my favorite junkyard. I thought it was a 465/205 set-up, but after finding and cleaning off the ID plate, it says it's a Rockwell Standard T221 N6, Ratio 1.94, Serial 7 68 0309. The 4-speed married to it has casting numbers:
H 17 8
2
GM
3901127
The rig has a 10-spline output shaft.
I checked the tranny's casting numbers against another 2WD known 465 I have and they were the same, except for the first line [date] D 29 8 = April 29th, 1968. so the unit with the 4WD t-case was cast on Sept 17th 1968.

Since '68 was the first year of the 465 and [about] the last year of the 221, there must not be too many of these T-cases around.

I am thinking of a project blazer, I call the "Phantom of the Junkyard." It started with a '72 Blazer rolling frame w/rusty tub, roll bar and doors -- and not much else. A buddy donated a '72 front clip doghouse to get it out of his yard. I have a couple of 292 L6 cores kicking around. I acquired the rare 292-only 4WD crossmember from a board member, now I have the transmission and transfer case. I'm not sure what's still in the differentials. This will be a long term basket case project.
Originally, the idea was to build a mirror image of my '71 Jimmy [350, 465/205, Factory posi 3.73 12-bolt rear, D44 front] so I could cannibalize components to keep the good one running. Now it's morphing into its own personality. The rolling frame lost its 2 mid frame transfercase crossmembers long ago. I could try to get some from a junkyard, or fab some new ones out of steel tubing -- flattened and drilled ends and sectioned struts in between.
I can copy the factory skid plate, too.
If the 221 has a different spacing configuration than a 205, I can mount it where ever it needs to go. I'll need new propshafts anyway so custom ones will have to do. Maybe I could cap it off with a half-top, seems to be the new K/5 fad-- and fab a mesh screen for a tailgate, so the dogs don't fall out.
All I need is a lot more money.