Belvidere Ill. Post Office travel records for 1910-11..This letter seems to detail the inferior material of a marble window sill thickness....There was plenty of problems building it, slow contractor, inferior materials. not getting paid from the U.S. Gov..The post office was over due by 10 months and the contractor really got penalized for storage, fees, and over runs..etc...It seems a tough job to have a contract with the Government as they are fussy and will not pay you if you mess up....This is a few pages of a pair of ledgers I bought in and weekend auction. There were about 300 pages of letters and descriptions of the everyday building of the Belvedere, Ill. Post Office in 1910-1911. A very interesting account of the problems and money spent on building a building for the U.S. Government. Cost was a bit over $100,000..in marble and granite, structo, and tera cota.. copper covered windows, cast iron bars and windows, railings....probably less than your average home now..

http://fromthegonzo.wordpress.com/2008/01/14/us-post-office-belvidere-illinois-part-3/

this link above is what it was..and more info...