75-MM GUN M4 AND AIRPLANE MOUNT M6 TM9_1311_1943.pdf

M4
The 75-mm aircraft gun M4 is a modification of the M3 gun which is found in medium tanks. It differs from the M3 gun, only in having a seat for the spline machined in the tube. It was mounted on the M6 mount.

T13E1 / M5
A lightweight version of the M3 with a lighter thin-walled barrel and a different recoil mechanism that was used in the B-25H Mitchell bomber. Uses the same ammunition and has the same ballistics as the M3. Mounted on T13E2 aircraft mount.

The M4 gun assembly weighed 893 lb according to the PDF above, and the gun tube weighed 628 lb… I can’t find the weight of the T13E1.

Can anyone find this: TM9-312 75mm Gun T13E1 and Aircraft Mount T13E2?