the K7500 and K7400 will have ONE cap in either spot. meaning, the K7500 has a cap in one spot, and the other is empty, and vice versa for the K7400.
I can't remember specifically which one is which, so I hope you remember which one needs to get pulled out.
the "extra caps" are for a pincushion board if you have a 27" or larger tube. I can't remember if those Gauntlets had 25s or 27s... they're like the other Midway cabs but a little different.
now I'm not sure if having that extra cap would cause your ticking issue, but if you happened to pop the HOT having that cap in there, that will cause your ticking. without horizontal deflection, you can't have high voltage. the only other thing I can think of is that you made an error in your solder work elsewhere, perhaps a solder bridge between two joints.
I'm no scholar on the subject, but I suspect that the primary difference between the standard resolution K7400 and medium resolution K7500 is the jumper wire arrangement in the middle of the chassis and that either-or cap placement. there's probably some other shit that's different, but I'm also going to assume you blew the HOT having that other cap in the circuit, if it's even attached to horizontal deflection. I don't memorize anything with these at all, soo....
I'm not even sure which of the 3 transistors on the black heatsink is the HOT. I don't think it's the 3rd one, probably the middle one, and the first one is maybe the vertical IC?