Did anything come of the building of a flying KC-135? I was surprised no one took Jeff up on a pull from his molds for the wind tunnel model. T.O.'s will be available for the KC-135. There should be everything from airframe erection drawings to measured technical drawings within them. Boeing is amidst moving their historical records to the Museum Of Flight. They are down to two persons and rarely respond to requests from outside the company.
If you are still serious about constructing a KC-135 I would start in Dayton.
73554 1C-135(K)R-4-CD-1 IPB -- USAF AIRCRAFT MODEL KC-135
73567 1C-135(K)T MODEL KC-135 SERIES TANKER
73580 1C-135(K)T-2GA-1 GENERAL AIRCRAFT -- SUPPLEMENT
73581 1C-135(K)T-2GA-1 GENERAL AIRCRAFT -- SUPPLEMENT
73584 1C-135(O)B MODEL OC-135 SERIES B (OBSERVA
73585 1C-135(O)B-1 PARTIAL FLIGHT MANUAL -- OC-13
73586 1C-135(O)B-1 PARTIAL FLIGHT MANUAL -- OC-13
73587 1C-135(O)B-1CL-1 PILOTS ABBREVIATED FLIGHT CRE
73588 1C-135(O)B-1CL-1 PILOTS ABBREVIATED FLIGHT CRE
73591 1C-135(O)B-1S-10 PARTIAL FLIGHT MANUAL -- OC-13
73592 1C-135(O)B-1SS-9 PARTIAL FLIGHT MANUAL -- OC-13
73593 1C-135(O)B-4 IPB -- OC-135B AIRCRAFT (CHRYS
73609 1C-135(R)-1 FLIGHT MNL -- USAF SERIES RC-1
73610 1C-135(R)-1 FLIGHT MNL -- USAF SERIES RC-1
73624 1C-135(R)C MODEL RC-135 SERIES C
73632 1C-135(R)S MODEL RC-135 SERIES S
73639 1C-135(R)V MODEL RC-135 SERIES V
73753 1C-135-1462 REMOVAL & REPLCMT OF WING/AFT
73754 1C-135-1462C REMOVAL & REPLCMT OF WING/AFT
73755 1C-135-1462D REMOVAL & REPLCMT OF WING/AFT
73929 1C-135-38 AIRCRAFT STRUCTURAL INTEGRITY
73930 1C-135-38 AIRCRAFT STRUCTURAL INTEGRITY
73960 1C-135A MODEL C-135 SERIES A
73961 1C-135A(II) MODEL C-135 SERIES A -- CONFIG
There are perhap another 100 or so available. Consulting a retired KC-135 maintenance crew member will probably get you more than you could ever hope for.
Good luck