M-151 - [Project] Long-range bomber, twin-engined
M-152 - [Project] Commercial flying boat, 63000 lb
M-153 - [Project] Commercial flying boat, transatlantic, 100000 lb
M-154 - [Project] Pan Am flying boat, 54000 lb
M-155 - [Project] Pan Am flying boat, 55000 lb
M-156 - "Russian Clipper" four-engined ocean transport, Russia, 1938
http://www.secretprojects.co.uk/forum/index.php?action=dlattach;topic=5808.0;attach=62586;image
M-157 - [Project] four-engined ocean transport
M-158 - [Project] TWA land trasnport a/c, 70000 lb
M-159 - [Project] Navy observation scout
M-160 - [Project] Navy 4-engined long-range patrol boat (M-160A, M-160B; engineering 1939)
M-161 - [Project] Army high-speed, twin-engined bomber
M-162 - Mariner; 162 XPMB-1/XPBM-1A/PBM-1/XPBM-2, 1939/1941; 162A 3/8 scale model, 1937; 162B PBM-3/XPBM-3E/PBM-3R, 1942; 162C PBM-3C/XPBM-3D/XPBM-3S, 1942; 162D PBM-3D, 1944; 162E PBM-4 [Project]; 162F XPBM-5/PBM-5, 1944; 162G XPBM-5A/PBM-5A 1945; 162Com export commerical Mariner [Project]; 162W 45000 lb Mariner [Project]
M-163 - [Project] 4-engined long-range commercial ocean transport
M-164 - [Project] 4-engine 27,500 lb bomber
M-165 - [Project] twin-engined bomber
M-166 - [Project] production M-139WH-3 export bomber
M-167 - Maryland; XA-22 twin-engined attack bomber, 1939; French export 167-A3 (M-167-F1, -F2, -F3, 1939; 167-B3 (Maryland Mk I), 167-B4 (Maryland Mk II) 1940/1941, 167-H1, 'H2 (Dutch, cancelled)
M-168 - [Project] Navy high-speed, single-seat Navy fighter
M-169 - [Project] twin-engine heavy attack bomber
M-170 - Mars 4-engined flying boat; M-170 prototype XPB2M-1/transport conversion XPB2M-1R, 1942; M-170A JRM-1 cargo transport, 1946; 170B JRM-2 cargo transport, 1948/JRM-3 conversion, 1950; M-170C [Project] 165,000 lb commercial flying boat
M-171 - [Project] long-range, high-speed patrol bomber
M-172 - [Project] M-172A/172B export bomber
M-173 - [Project] M-173A 24-pax commercial transport, M-173B 27-pax commercial transport, M-173C Army twin-engined, high-speed bomber
M-174 - [Project] Army attack bomber
M-175 - [Project] Army attack bomber
M-176 - [Project] Army attack bomber
M-177 - [Project] Army attack bomber
M-178 - [Project] twin-engined bomber
M-179 - Marauder; M-179 B-26; M-179A B-26A/B-26A-1, 1942; M-179B B-26B, 'B-1, 'B-2, 'B-3, 'B-4, 'B-10, 'B-15, 'B-20, 'B-25, 'B-30, 'B-35, 'B-40, 'B-45, 'B-50, 'B-55, AT-23A; M-179C
B-26C-5, 'C-6, 'C-10, 'C-15, 'C-20, 'C-25, 'C-30, 'C-45, AT-23B; 179D XB-26D; M-179E B-26E; 179F B-26F-1, 'F-2, 'F-6; M-179G B-26G-1, 'G-5, 'G-10, 'G-11, 'G-15, 'G-20, 'G-21, 'G-25,
TB-26G-20, TB-26G-25
M-180 - [Project] Navy twin-engined, long-range patrol bomber
M-181 - [Project] Navy twin-engined, long-range patrol bomber
M-182 - [Project] XB-27 twin-engined supercharged bomber
http://www.secretprojects.co.uk/forum/index.php/topic,242.45.html
http://www.secretprojects.co.uk/forum/index.php/topic,242.60.html
M-183 - [Project] Navy twin-engined, long-range patrol bomber; M-183D medium-range patrol bomber
M-184 - [Project] Navy patrol utility (one or two engines)
M-185 - [Project] Navy patrol utility (one or two engines)
M-186 - [Project] Navy amphibian patrol utility (one or two engines)
M-187 - Baltimore; XA-23 [Project]; 187-F1 French reconnaissance bomber (cancelled); 187-B1
Baltimore Mk I, Mk II, Mk III; 187-B2 Baltimore Mk IIIA, 187-B3 Baltimore Mk IV, Mk V; 187-B4 Baltimore Mk VI (cancelled); 187-H1 Dutch reconnaissance bomber (cancelled)
M-188 - [Project] Model 186 modified for export
M-189 - [Project] XB-33 twin-engined, high altitude medium bomber
http://www.secretprojects.co.uk/forum/index.php/topic,242.45.html
M-190 - [Project] XB-33 four-engined high altitude medium bomber, B-33 (400 cancelled)
http://www.secretprojects.co.uk/forum/index.php/topic,242.45.html
M-191 - [Project] twin-engined bomber
M-192 - [Project] twin-engined torpedo bomber
M-193 - [Project] 250,000 lb cargo transport (modified JRM)
M-194 - [Project] four-engined "Lone Ranger" heavy bomber
M-195 - [Project] twin-engined, high-speed medium bomber
M-196 - [Project] twin-engined, multi-purpose medium bomber; M196-1
M-197 - [Project] twin-engined medium bomber
M-198 - [Project] twin-engine, high-speed patrol bomber
M-199 - [Project] 145,000 lb cargo land transport (modified JRM)