No, TMO 2.5 is the last. First, a few questions:
1. What folder did you install SH4 in? You should avoid the "C:\Program Files (x86) \Ubisoft" folder like the plague. Re-install it to a folder of your own naming.
2. Did you use the Windows archive manager? If so, then you may have double TMO folders. Look in your MODS folder, and you should see a folder "TriggerMaru_Overhaul_2-5". Look inside of that folder, and if you see another folder "TriggerMaru_Overhaul_2-5", then there is the issue. Be sure and de-activate TMO, and then drag that second TMO folder out from the other, and re-activate TMO. (You'll probably have to put it in a temporary folder.)
The "
TMO_25_small_patch" mod gets rid of the Terrible Tambor, which the only problem is that your boat won't upgrade. It is advisable to use it, unless you put
RSRDC (Run Silent Run Deep Campaign) on top of TMO, then you wouldn't need it. If you do use RSRDC, be sure and check-out
Ralles RealModPack with TMO / RSRDC and OTC (Optical Targeting Correction).