Try and upload a few photos, here’s how https://www.antique-locks.com/showthread.php/3328-How-to-upload-images-to-your-posts
Even without the photos, the 1k11 you mentioned should be easy to differentiate from others as they are all pretty distinctive.
The 1k11 was their flagship called the Battleship, close-shackle with a ground-off cast case, notably without laminations or rivets and used a 6 gauge (SWG)pin key.
The 1k21 Cruiser is close-shackled but otherwise the opposite- it has both a laminated case and is held together by rivets, and used an Ø11/64″ bore pipe key with a very distinctive offset bit.
There’s also the possibility yours might be an older Corvette, which was a sort of early lightweight pressed steel version of the cruiser (well, sort of), but they weighed about as much as an empty crisp packet. In contrast, you wouldn’t want to drop either of the previous two on your foot wearing flip-flops, but all will be revealed once you add some photos.
