Illinois Terminal ITC Detailed Estimate for Interlocker & Routing Envelope 1949

Description

The item is a two page "Detailed Estimate on Illinois Terminal & L. & M. (Litchfield and Madison) Automatic Interlocker , South of Worden Ill." and it is folded and placed in a Illinois Terminal Routing Envelope.  The estimate is dated November 14, 1949.  The routing envelope is Form 106-7.
The estimate is torn in several places along the creases.
The routing envelope is used and has four previous entries which I can't read very well.  With electronic messaging, routing envelopes are no longer relevant, but I think they are a nice piece of history.
Please look at the pictures closely as they are part of the description.
***********
We ship to the continental 48 states and Canada.
Canadian buyers please note the following.
Please wait for an invoice before paying and the minimum shipping charge is .75 USD.
We will combine shipping except on large items.
Buyer please email when waiting for multiple items to finish.
Buyer please email when ready for an invoice.
Shipping is USPS Parcel Select with tracking.
Returns of unopened items accepted within 14 days.  Buyer pays return shipping and tracking.
Paypal only.
Please email with any questions.
Thank you for looking.