2 medieval Spanish coins [επιλυμένο]

Hi! I have these old Spanish coins, the names of the rulers aren't quite visible unfortunately. The composition doesn't look like silver or billon, maybe they are fakes. Could anybody kindly assist? Thanks in advance!

Weight: 5,10g Diameter: 27mm

Might be from Castile-Leon, something from Enrique IV? N#50760

Couldn't find anything with similar composition/weight/diameter.

Weight: 2,65g Diameter: 21mm

Found some similarities with Isabella and Ferdinand coins, but no matching yet. 

N#192935

Three towers: San Marino?

Yes, it has three towers, but as far as I know, it's not the same three towers. Rather the Castilian coat of arms like three towers:

The upper coin is a Catholic Kings 1506-1566 4 Maravedis.  Trying to be a little more specific, I could rely on what looks to be a P on the right side of the tower.  If that is the case, it might be a 1543-55 Ivana and Carolus  from the Coruna mint???

In the lower coin the large RVS on the left image and the RX on the right are the Felipe IV 1658-59 resurfacing PVS/RX resello taking the value of the coin back down to II maravedis from the weight and diameter of the coin.  The original coin could be either a Felipe II 1598-1602 2 maravedis, in which case the resello sequence would be  1603 IIII - 1636 VI - 1652 4 - 1658 PVS/RX II, or a Felipe III 1602-21 4 maravedis in which case the resello sequence would be 1636 VI - 1652 4 - 1658 PVS/RX II.  The 1636 VI is right below the RX on the right image, and was struck at the Madrid mint.   It is a nice coin, and fairly unusual to se the PVS/RX so well centered.  

Robhar: Thank you very much my friend, you have been a great help! :)

Is that possible, that the first one is a 2 Maravedis? The weight would suggest that one, but I might be wrong. My coin is 5,10g, according to Numista the 4 Maravedis is 9,6g, and the 2 Maravedis is 4,8g, which is closer in weight, even if it's heavier than mine. It's just an observation, I'm not familiar with that era and area of coins.

I would not have guessed the second one would be countermarked (never had such a coin so far), wasn't even searching between those, thought them to be rarer that to be obtained for the price I paid for this two. I will have to be more thorough from now in!

Good observation on the weight of the first coin.  But the design, with the partial arcs, is that of the 4 maravedis.   And check the diameter of the 2 maravedis, which I think is considerably less than 27 mm.  

And the second coin is a very interesting coin in that the PVS/RX is large, centered, and fairly complete.  But the feature directly below the RX has be be explained.  And it is a Felipe IV 1636 VI maravedis resello.  Both  1636 and 1658-9 resellos together indicate the full sequence was struck.  

If you have continued interest in the Spanish resellos, “Los Resello en los Maravedis del Siglo XVII” by Lopez de la Fuente is a very good inexpensive guide available on Amazon.  “Los Maravedis de los Austrias” again by Lopez de la Fuente is a detailed catalog of the maravedis denominated coins from about 1500 to the late 1600's.    Both highly recommended.  

As far as I can see, the 2 Maravedis has a 30mm diameter, which isn't far away from the 27mm I have here, though the 4 Maravedis has only 28mm, which is closer, indeed. But I might be looking at the wrong coin? N#48590

The subject is interesting, though I possess no other pieces from this era, these two too were given away almost for free by their previous owner, since she couldn't identify them at all, only that they are something Spanish. I was looking through the internet for more info on the coins after your comment and found the books you mentioned, being recommended by others too, so they must be very helpful, no doubt! But until I have way more coins to try and identify from medieval Spain, I'll have to just resort to such online helpful experts as yourself! :)

O Numista o Lopez de la Fuente esta equivocado.