It seems there are quite a lot of places to look for thoughts about the various words for swords. I offer passages from three, in chronological order:
Ramshorn (1841) gives the following commentary about some of the words for "sword":
Gladius, the sword for cut and thrust; Ensis, the longer sword, more adapted for the blow or cut, hence with heroes and gigantic people: Graviter gladio caput percussit. Hirt. Stricto gladio transfigit puellam. Liv. Hectoreo perculsus concidit ense. Cic. Acinaces, the crooked Persian sabre; Sica (secare), a short cutlass used by banditti; Pugio (pungere), a stiletto, dirk; Tibi extorta est sica de manibus. Cic. Cæsare interfecto statim cruentem alte extollit Brutus pugionem. Id.
Döderlein (1858), meanwhile, gives the following:
Gladius (from κλάδος) is the usual, ensis (from ansa?) the select and poetical name for a sword. Quintil. x. 1,11. (v. 188). Pugio (from pungere) is a dagger, as a fair and openly used soldier's weapon, on a level with the sword; whereas sica (from secare) is the unfair and secret weapon of the bandit, on a level with poison.
From these, it seems that gladius would work, but ensis is perhaps less appropriate. I'd vote against both mucro and telum, as the former usually refers to the point of a sword rather than the weapon entire and the latter to any kind of weapon whatsoever.
The most specificity I've been able to find is in a translation of Aulus Gellius's Noctes Atticæ, X.25. The original reads as follows:
Telorum iaculorum gladiorumque uocabula, quae in historiis ueteribus scripta sunt, item nauigiorum genera et nomina libitum forte nobis est sedentibus in reda conquirere, ne quid aliarum ineptiarum uacantem stupentemque animum occuparet. Quae tum igitur suppetierant, haec sunt: hasta, pilum, phalarica, semiphalarica, soliferrea, gaesa, lancea, spari, rumices, trifaces, tragulae, frameae, mesanculae, cateiae, rumpiae, scorpii, sibones, siciles,
ueruta, enses, sicae, machaerae, spathae, lingulae, pugiones, clunacula.
De 'lingula', quoniam est minus frequens, admonendum existimo lingulam ueteres dixisse gladiolum oblongum in speciem linguae factum, cuius meminit Naeuius in tragoedia Hesiona. Versum Naeui apposui:
sine mi gerere morem uidear lingua, uerum lingula.
Item 'rumpia' genus teli est Thraecae nationis, positumque hoc uocabulum in Quinti Enni annalium XIV.
John Carew Rolfe (1927) gives the following translation of this passage:
Once upon a time, when I was riding in a carriage, to keep my mind from being dull and unoccupied and a prey to worthless trifles, it chanced to occur to me to try to recall the names of weapons, darts and swords which are found in the early histories, and also the various kinds of boats and their names. Those, then, of the former that came to mind at the time are the following: spear, pike, fire-pike, half-pike, iron bolt, Gallic spear, lance, hunting-darts, javelins, long bolts, barbed-javelins, German spears, thonged-javelin, Gallic bolt, broadswords, poisoned arrows, Illyrian hunting-spears, cimeters, darts, swords, daggers, broadswords, double-edged swords, small-swords, poniards, cleavers.
Of the lingula, or "little tongue," since it is less common, I think I ought to say that the ancients applied that term to an oblong small-sword, made in the form of a tongue; it is mentioned by Naevius in his tragedy Hesione. I quote the line:
Pray let me seem to please you with my tongue,
But with my little tongue (lingula).
The rumpia too is a kind of weapon of the Thracian people, and the word occurs in the fourteenth book of the Annals of Quintus Ennius.
Of the terms in Rolfe's translation, "small-sword" ("a light one-handed sword designed for thrusting which evolved out of the longer and heavier rapier of the late Renaissance") seems the most appropriate for the images in your post. If he is to be trusted (I'm agnostic on the point), then lingula is probably what you want. I suppose you could add doctoralis, but given the paucity of uses one finds for the sword today that seems to me to be a touch scrupulous.