Please post some pictures

[Edward Tinker]

Seems like that part is there

FAQ
http://forum.lugerforum.com/showthread.php?t=13121

27) What is a MAUSER BUMP?

Can anyone explain to me the real thinking Mauser had when they produced their early Lugers with the No Mauser hump and then some were intermixed with the Mauser hump and finally all were produced with no Mauser hump?

The early Mausers had mixed humps and no humps, but for instance, the Gs seem NOT to be humped, but they all have a thickened back where the hump is to better contain the rear axle pin during the rearward most movement of the receiver forks. The humped Mauser simply had some of the thickened rear frame REMOVED to form the hump.

The Hump but it is formed at the very rear back of the frame above the lanyard loop. The back of the frame on DWM's is straight up vertical. Some K-dates, G-dates and 1936-S/42 Mausers are also straight up or vertical. The Hump causes the rear of the frame to not be vertical, it has a curved appearance to it. You can easily see it from the side. The Mauser Military Lugers are the only ones that have the HUMP, I think! It is interesting Mauser elected to remove that section of metal to return the frame length to the same as a DWM Luger!

Can anyone let me know when Mauser started building the rear frame "bump" to prevent the rear toggle link pin from falling out when the toggle assembly was in its full rear position ?
I have seen some Mauser S/42 coded Lugers without this "bump".
Should this "bump" occur on all Mauser Lugers, i.e. K-dates, G-dates, byf's, Banners, etc. ?
Some K dates had them on them and some Ks had a thickened back edge so if they wanted the HUMP, they could machine metal off the bottom edge of the thickened wall, it was an attempt to keep the rear axle pin from slipping sideways under full recoil. MOST Mausers will have it, but they would leave it out for a while then put it back in. Some Navy Lugers approached this problem from a different angle, they made the head of the pin LARGER.