A pity for the lack of database even if i saw people posting some lists.
Concerning the small numbers, i asked exactly because they were likely rare events, thus of quite relative interest.
I have also some other scattered hints/potential events (in addition to the two above-moentioned)
Almirante Cervera claim
During the remainder of 1937, she sank two Republican coast guard units along with a merchant ship. She also shot down a bomber aircraft that had tried to dive-bomb her three times. The cruiser played a central role in the capture of the 9,900-ton government transport Marqués de Comillas.
Republican claim, in Bilbao
El 5 de enero por la tarde, la aviación nacional efectúa un ataque a la flota que estaba amarrada en puerto, y el C-2 derribó un trimotor. A
There is some reported loss on the day?
Quite an interesting (and more realistic) Republican claim
July 30, 1937 Three Heinkel He.59 AS / 88 seaplanes of the Legion Condor south of Barcelona, 15 miles from Areniz de Mar, were observed from afar by a Republican convoy. The Greek steamer “Laris” marched with military cargo under the Panamanian flag and with the name “Chepo”, accompanied by the republican destroyers “Almirante Valdés”, “Escaño” and torpedo boats No. 31 and No. 41. The planes attacked the ships, achieving hits in them. In turn, one of the Heinkel He.59 aircraft was hit by anti-aircraft fire and made an emergency landing at sea 15 miles south of Blanes. The plane and its wounded crew were saved by the cruiser “Canarias” who took him in tow and delivered to Pollensa, at 08.00 o'clock the next day. According to an official AS / 88 report, as a result of the attack, the merchant ship Chepo got into the stern, 4 sailors died on it, and he ran aground near Calella where he was hit by a 250-kilogram bomb four days later. The destroyer Almirante Valdés had a damaged nose, and torpedo boats received even more significant damage from machine-gun fire.
Interestingly, it was the biggest incident with Soviet advisors casualties in surface action of the conflict.
motor torpedo boat No. 31 suffered damages with 1 Spaniard KIA, 3 Soviets WIA and 1 Spaniard WIA
motor torpedo boat No. 41 grounded and lost after heavy damages but less casualties (only 2 Spaniards WIA).
Also the Soviets quite neatly describe the AA fire from the MTB as ineffective for insufficient elevation angle of the machineguns.
I found a couple of lists posted abbout the losses of He.59 seaplanes during the war (10-12 planes) but none match the entry for July 1937.
Moreover the description of the plane is more like damaged rather than shot down: more likely by “Almirante Valdés” and “Escaño”, than MTB.