With the help of Raf, I've managed to get replace the 29f400 with a socketable 28f400. The result can be seen in the pictures below.
Good news is that it works perfectly and that means several things:
* Both 29f400 and 28f400 can be used
* I changed the BIOS from a Mexican one to a USA one and worked perfectly.
* This is an SF2 cartridge, which might be even better given the peculiarity of the encryption in this game (data not encrypted, code encrypted).
* It´s much easier and safer now to attach the probes from the signal analyser.
* Nope, I can't get back to life dead cartridges yet....
I will setup everything this weekend and let's start seeing what's going on.