Re: Drawings of Howe or Pony Truss wooden bridges as used on the Silverton Branch?

I have 3 D&RG Drawings for 64 foot Howe truss bridges dated 1884,1888, and 1905. I
also have a John Maxwell tracing ( or perhaps redraw) of an 1889 Rio Grande Western 64 foot bridge.
The Rocky Mountain Region of the NMRA published in the August 1960 issue of their Publication "The Helper" an set of plans by
Billy Bowen and John Horan. These were of the Hermosa Bridge and based on their measurements with reference to the 1889 RGW Drawing. There is a note in the article which states that in 1936 5 spans were replaced on the Silverton branch. and 2 similar spans were replaced with steel bridges. All 7 of these were replacements for bridges from 1914.

All 5 of these drawing have differences in some timber sizes and some of the Iron parts.
I believe that the hardware that we made for the, 1/4 scale, San Juan Engineering 64 foot Howe Truss bridge was made from the Helper Drawing or was based on information that came from it.

The Gazette also published the set of plans which were used in the San Juan Engineering Kits I don't recall which issue though.

I know that this probably won't be of much help, but the drawings are either too large for my scanner and/ or may have copyright issues.