On both the classicshaving vintage DE and Merkur 15C, the blade sticks out on the sides. Besides the Futur and Vision, are there any Merkur razors that completely encase the blade, leaving only the cutting edges exposed? Any Muhle heads fit the bill?
While I can't tell you which Merkurs do, I just checked and neither my 38C or 1904 cover the blade tabs entirely.
Wish I could be more help.
Cheers,
Rick