This battleship came with a yellowed case and several likely aftermarket worn pad-printed keycaps. I replaced the original case with a NOS case sourced from Unicomp. The original terminal-centric legends were largely replaced with a Wheelwriter keycap set recovered from a beyond recoverable keyboard assembly with some standard PC Enhanced Keyboard keycaps mixed in. The pearl Esc, and pebble Fn, stepped Ctrl, 1u backspace and old-style Windows logo keycaps were from Unicomp. I also performed an "Erase-Eaze" split-spacebar mod using the "Code" and spacebar keys sourced from the same aforementioned Wheelwriter assembly. This keyboard was also featured in my Differences between and classifications of 122-key Model Ms comparison topic.
The Type I 122-key Model M Function Key Keyboard was the largest and heaviest Model M available. The design is largely an internal rework of the Model F-based equivalent, swapping out the capacitive assembly for a membrane one and changing the bottom metal pan the keyboard assembly sits to a plastic one. As such, it's almost impossible to tell the difference between the 122-key Model Fs and these Type I "M122s" from a visual inspection of the front or sides. These also operate with many of the same terminals "F122s" operate with, including the IBMs 3179, 3180 and 3205. These also retain the dual-setting riser-style feet and straight-shaped metal-jacketed 240-degree pin arranged DIN plug "F122s" had, and could have their 24-key function key block labelled in either "Cmdxx" or "PFxx" nomenclature.