There's actually a fourth mono mix of "Leopard-Skin Pill-Box Hat", to be found on the 45rpm single released in numerous countries in the spring of 1967. This sounds a lot brighter than any of the mono mixes found on LP. The vocal (only) has a noticeable echo, and both the vocal and the higher frequency percussion have much improved clarity compared with any of the LP mixes. The balance between the three electric guitars is rather different than on any of the LPs. As those who have heard the single will know, this version is also heavily edited, losing much of the introduction as well as the third and fifth verses.
I'd guess that the song was remixed in 1967 specifically for the single release rather than being an edit of a fourth mono mix made for the album.