I just noticed this virtual version of a photo exhibit from 2023 about Barcelona in the late 1930s:
https://carmenthyssenmalaga.org/exposicion/memoria-de-las-calles
It's a bit unwieldy to walk through it on-screen but check it out for a non-touristed Las Ramblas and a non-widened gotic streetscape -- it reminds me of those photos of Paris and other cities before urban renewal projects took hold.