Prototype keycaps can use this as a major https://item.taobao.com/item.htm?spm=a230r.1.14.23.39613a778xgx7w&id=563797126524&ns=1&abbucket=17#detail 130
Shell casing can be equipped with a column of 68 keys is based on build
FIG right keys may be added with exactly one column 72, and exactly same size and tada68 keyboard, can be common housing:
Estimated PCB72 with the column to their own design
Mainly positioning plate may be more downright some
Hope you can caploc completely abandoned, and replaced the esc key, into the upper left corner - esc key, add a space Fn, to the right spaces removed ctrl, add a key App,