First, Adam, thanks for beating me to this one!
Better 3 years late than never! I must have overlooked this one then!
Charles: Unfortunately, there NEVER was anything standard about the B&O. That's why so many mass-produced models of B&O locomotives and rolling stock are very inaccurate, not to mention structures. B&O built and rebuilt to fit specific needs, for a given time, place, and situation, at the least amount it cost to do the job, no more. So in most cases, no one item of B&O was ever identical. Yes, they had classes of locomotives, rolling stock, etc., but where duplication occurred was only on the most basic design of that class, but you had to get down to specifics to see where the differences were from unit to unit.
I have never seen any plans for, or instances of a concrete B&O passenger shelter. I seriously doubt that any such thing ever existed. The only concrete B&O shelter of any kind that I've ever seen is a communications shelter that held company phone equipment along the ROW used by ROW personnel, or the crew of a particular train where and when needed.
The B&O RR Historical Society has many plans of stations and other structures in its archives, but most of these have not yet been digitized and are not on line. The same would also apply to the Hays T. Watkins Research Library at the B&O Museum in Baltimore. Since most everything that B&O did was unique from item to item, my question to you is are you trying to model something on a layout? If so, what location and what time period are you trying to model? Narrowing down location and time period can go a long way to helping you get the most accurate model of the prototype as possible for your time and modeled location.
Wade Rice
Member, B&O RR Historical Society
http://www.borhs.org
Daniel Willard (1860-1942) and Jervis Langdon, Jr. (1905-2004) - Two of B&O's best presidents and managers!
President Leonor Loree (1858-1940) brought the B&O into the 20th century!
but have you checked with the BORHS or the website below?