After MP34 recently pointed me to
Getty Images to find some more pictures of the
Orioles all orange uniforms, I came across this amazing picture:

This is the first picture I'd ever seen of Brooks Robinson in the rarely seen 1968-1969 Orioles vest. In fact, after seeing this, I realized I have not seen very many photos of this uniform which was only worn a few times and then retired.
Once I came across this picture, the search was on for more pictures of the Orioles vests. I found pictures from an auction of a Brooks Robinson vest

as well as a Curt Motton jersey:

I also asked Paul Lukas from
Uni Watch if he had any pictures, and he put the word out to Rick Pearson who provided these shots (thanks Ricko!):

Since the caption under the Paul Blair photo looks like it was from Sports Illustrated, I checked out the SI Vault, and searched the 1968 - 1969 issues and found an additional shot of Brooks

as well as this great SI subscription ad featuring Brooks and Elrod Hendricks:

I was only able to find one other picture of the vest on Getty Images:

Since I have the 1969 Orioles ALCS and World Series programs, I checked those as well, and was able to come up with a few more pictures, including this shot of Frank Robinson:

another shot of Brooks:

a nice series of shots of Dave Johnson and Mark Belanger:

another shot of Dave Johnson:

and another shot of Paul Blair:

I really like the look of these vests, and would enjoy seeing the Orioles bring them back as an alternate. I'm not sure why the Orioles discontinued the vests, but I could have sworn that I read at one point years ago that the pitchers didn't like them so they stopped wearing them. Don't quote me on that, but I seem to remember reading that somewhere.
I'd like to say thanks to MP34 for directing me to Getty Images where I found the Brooks picture that started this search as well as the help from Paul Lukas and Rick Pearson that led me to check out the SI archives and find a few extra shots.
If anyone has any other shots of the Orioles in their vests from 1968-1969, please let me know, and I'll add them to this pictorial collection.
UPDATE: 2/2011
I came across another picture of the vests in which something doesn't look quite right:

This is picture of Brooks Robinson, Paul Blair, and a young girl's head on Andy Etchebarren's body. The
picture comes from this blog where the young girl in the photo shares some of her other pictures taken with various Orioles players.
Apparently this was a cardboard cutout for fans to have their picture taken as an Oriole at one of the annual Bethlehem Steel Family Nights that used to be held at Memorial Stadium. Its interesting that the cutout that was used for taking pictures was a uniform that the team rarely wore.
UPDATE: 6/2011
Two more additions to the collection:
Boog Powell:

Eddie Watt:
UPDATE: 5/2012
Another addition to the collection:
What a great shot of Mike Cuellar with the original Memorial Stadium scoreboard in the background on May 24, 1969.
UPDATE: 7/2016
These pictures are from May 21, 1969 against the Twins:
These pictures are from a few days later against the A's on May 24, 1969:
And here are a few shots of Davey Johnson: