Sapinero Depot

I am scratch building the Sapinero depot in O guage. I have a copy of John Maxwells drawings of the depot which are only a perimeter sketch showing the location of the doors, windows, freight doors and interior walls. My problem is that unlike a copy of his Cimarron depot plans which I have, no dimensions or drawing is given for the walls. This depot is unusual in that it has high wainscoting. My best estimate is that it is four feet high before what I'll refer to as the chair rail molding. Windows appear to be close to the Grandt Line part no#300-3723 which is a 36' x 82' RGS depot 4 pane style window. Photos of the depot are in the following books Trails Among The Columbine series 1989 page 72 & 73. Trails Among The Columbine series 1988 page 168. Colorado Rail Annual No#14 page 73 and Twlight On The Narrow Guage page 35. any help would be appreciated.