This coin appears to match the design of GB 212, but the reverse looks bizarrely stretched and distorted. Also, there appears to be a strong die clash of the sun's rays visible on the obverse surrounding the lower part of the eagle's body, and another strong die clash of the eagles wing's visible on the reverse in the sun's rays.

I am away from my SUR coin but yours seems to be the same without the SUR and maybe other reengraving.

Things I have noted on my coin (x-Walrafen):

Planchet is cast, edge is reeded, coin is struck not cast. Reeding is the same as the other GRO 2 pesos. Probably the planchet was punched out of a cast strip and reeded in the reeding machine.

Heavily reengraved eagle die from GB-212. Lettering, rays, sun face reengraved, sun eyes lowered, SUR added above the eyes. Lettering enlarged--on the Y before LEY you can see the bottom serriff of the original Y on the stem of the (enlarged, reengraved) Y. Bold, dramatic lettering on all the letters of REFORMA, LIBERTAD, JUSTICIA Y LEY

Late die state--you can see clash marks from the eagle's wing in the sun rays

Eagle die--very late die state of GB-212

It appears the coin was placed in circulation, it is now in XF or better condition, couple of rim taps, strike is average or above average, 26 or so grams mass.

Possible order:

GB-212 struck

GB-211 struck after GB-212 using eagle die of GB-212. Clash marks of sun rays on GB-211 eagle die that are not on the GB-212 eagle die strike (I have example of this GB-211 clashed eagle die, as well as an example that is not clashed, suggesting the eagle die clash occured during striking of GB-211 and not GB-212)

GB-UNL struck using the same GB-212 and GB-211 eagle die, but in a much later die state. Very poor eagle die. I am away from my notes, there are two GRO 2 peso GB-UNL strikes. One (the more common one) uses the GB-212/GB-211 eagle die

GB-212 sun die reengraved, used with very late die state GB-212/GB-211/GB-UNL eagle die, your coin struck (die trial?) (it looks like the REFORMA on your coin has also not been reengraved)

GB-212 sun die SUR added, REFORMA reengraved (final reengraving) and my coin struck (pattern for a larger issue that was never made?)

Important: the SUR is in the die and is not a counterstamp like many people think. Photographs suggest it is a counterstamp but it is not, it is in the die

The 1915 GRO 2 pesos sun die was refinished from a 1914 coin. I can't remember if it was from the GB-UNL (more common strike) or some other 1914 coin

My conclusions: This was a pattern strike at the GRO mint using a die made up for the job (the Sun die), and using a die that was laying around (eagle die). It is probably just coincidence that both the GB-212 dies were used, as the eagle die had been used to strike three different coins.

This was probably done later in the 1914 striking run, as the GB-UNL-common are usually light weight planchets, like the GB-218, suggesting a late strike, and my coin was, I believe, struck after the GB-UNL-common.

An important fact: this coin was made at the GRO mint (wherever it was) because they had access to the dies, access to the planchet punch and reeding machine, and had a skilled engraver who could modify the sun die.

This wasn't the work of a counterfeiter, or a mint sport made up "after the fact". It appears this pattern design was not used for continued striking of the 1914 coins or the 1915 coin. This coin was probably struck before the 1915 GRO 2 peso, as they refinished a sun die used on an earlier (1914) striking instead of making up a SUR die for the 1915 strike.

My final conclusion: I disagree with Joe Flores and agree with Vern Walrafen and Richard Long in that this is a significant coin. You appear to have an earlier version (die trial?) of the SUR coin, and therefore your coin is significant in that it shows the die progression and shows mine is not a mint sport. Richard Long thinks he has seen another SUR coin, or a coin similar to yours, or maybe saw my coin before Vern Walrafen got it, back in the past. He might have sold a similar piece to yours in 1993 (?) or so