[ArditoCorsaro]

You're right sid.
Now i tell you a thing: in 1943, doenitz need some transport sub for send to far east.
Italian ocean going sub (based in bordeaux, france) was much big than u boots in size, and doenitz ask 10 italian fleet boat (becoming too old for patrol in atlantic, but good for transport missions.) and give 10 7c u boot to regia marina.
(the veterans crew of betasom (bordeaux), go to danzig and began to train on these 7c. they was ready for go in patrol but the armistice have block all. and the majority of the crew at the end, go to fight with X° flotilla mas, on midget subs in mediterranean, or in "marines" infantry.).
So regia marina had for a period some 7c. (And for example, platino sub class, of 600 series, was much similar to a 7c. but not only. also the tritone class, was much similar.).
So we need also a 7c. you're right.
p.s. Thank you!