Could a military expert ID this uniform?

I’m working on the Wikipedia page for Juan Pujol. I’ve found an excellent image, but I need to find when it was taken, and by whom. It probably dates from the Spanish Civil War, but Pujol served on both sides in that war.

Not a military expert but the prominent ‘7L’ on his cap and leads me to believe it’s his Republican uniform. As the wikipedia article already says:

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It doesn’t say what unit he served in (fought is inappropriate given his never firing a shot), but I think it extremely unlikely that whatever unit it was also had 7L as it’s number.

[Homer Simpson]D’Oh![/Homer Simpson]

Of course now it’s almost inevitable that an actual expert will come in an explain that it’s actually his Nationalist uniform…