Spaniards and an Irishman?
Looks like wall-to-wall Sephardic jews at the Consecrations to me 

Yeah, I'm sure you can tell that from these grainy / blurry pictures. I'm not seeing the typical physiognomy in profile LOL (i.e. the nasal profile).
So, of the initial Consecrands, the one that's intringuing would be Father Camilo Puga, and pre-Vatican-II-ordained priest. While the fact that Dominguez and Corral were not qualified to be priests or bishops would be a problem for assessing the validity of subsequent Ordinations / Consecrations they performed, +Puga was in fact a priest, properly educated before Vatican II, so where he was performing Ordinations or assisting at least in Consecrations, those would be presumed valid.
Plus, these were public Rites, witnessed by thousands, AND you had a priest (or two?) assisting ... so that would meet even Bishop Kelly's extreme (and frabricated) requirements for validity. I bet you could even find audio tape or even video tape of the Rites (if you reached out to the Palmarians).
So the 3 Spaniards were: Dominguez, Corral, and Fr. Puga
Fr. Donnelly (Irish) [very weak link to Jєωιѕн roots, as there are MANY Donnelly's who are not Jєωιѕн]
Fr. Sandler (US) [any relation to Adam?]
So the other two were priests as well, but Fr. Donnelly left them shortly thereafter, and ended up in Miami FL, dying in 1982.
Fr. Sandler left shortly after also, but then returned, left again, returned again, and died in Palmar in 1992.
But those two did not perform any consecrations for Palmar.
+Puga, however did, and the ones he performed are to be presumed valid, even if Dominguez / Corral's could be questioned due to their lack of training.