B&M railroad system maps

I just aquired a framed B&M railroad & connections map: but it's not dated. I've seen an 1898 version on line which is very similar - same background and details only mine has later information from 1900 + like the addition of the Fitchburg division, the realignment of the Central Mass RR north through Clinton as opposed to south throught the drowned towns of Boylston and West Boylston. So I know it's no earlier than 1900 but since it also has the Acton-Nashua line (as B&M) from Concord Junction as well as the reformatory branch of the Middlesex line also to Concord Junction I know it's no later than 1926. But I can't find anything on line that dates this. Anybody have a clue what years these system maps were produced in the early part of 20th century? due to the closeness in style and formatting to the 1898 map I'm positive it's within the 1900-->1905 range but I just don't know.

See this link for a picture of the 1898 map

http://en.wikipedia.org/wiki/Boston_and_Maine_Railroad

The one I'm talking about is the next iteration of this.

There was one from 1915. The B&MRRHS reproduced it and sent it out to the membership in an 8 1/2 by 11 (more or less) size a few years ago. Try them or the Salisbury Point guys. I don't know where you are but try taking a photo and hand it around at one of the shows. There's one in Wenham mass. Jan 6th, and you will find a lot of knowledgeable people there.