I use a JIS Japanese layout and was wondering how difficult it would be to get keycaps for this layout in the image. I am not sure if you are only using Unicomp or if there is another manufacturer. I think that the red keys are going to be unlikely or impossible to have made, but are the rest reasonable? I am concerned about the blue keys*, especially about the right shift and 1u backspace with an arrow legend. I think that the other blue keycaps can be made by Unicomp.
*The shift keys should have <“up arrow” Shift>.
Yes that key layout from your message is possible – you can select “International” layout and make a note of a link to your photo below. I will be ordering non-standard keys from Unicomp (I assume they have it available as long as IBM made it originally).
Yes all 1.75U keys are non-stepped – I am ordering a special mold cavity for this key.