Interesting, f1.4 sounds awesome, mine's f2, which is still nice. It's a soviet lens (esentially a copied zeiss biotar lens), with apparently a really nice swirly bokeh, and an adapter to use it on my sony a6400 costs like 25 euros, which is tempting :>. Aperture on it is a little finnicky, it likes to get kinda stuck around 5.6 sometimes, and I have to wiggle it a bit to get moving, lol. theres also something flying around, as I can hear the sound of something inside when I turn the lens around, but otherwise it seems to work just fiine.
Speaking of viewfinders, check out mine... It doesn't bother me really, gives character to the camera I guess, but whatever happened, its not the lens, and not the mirror, so the damage is somewhere deeper.

So this zenit ttl is just my dad's old camera, he used it back in the 80s, and it's been in the closet for decades. We hada conversation one day, he showed it to me, and I decided to take it for a spin, see if, and how it's working. Did a test roll, turned out fine, wrote a blog post about it :) I didn't had to fix anything. I just don't know if the light metering works, as I don't have the battery. The camera uses some old mercury batteries, and replacements are quite pricy. I don't really care that much to pay for it.
Your camera looks great, and that release button fits so well. Mine has these gnarly little spikes on top, as it's threaded for the cable, but it digs into your finger (unless something's actually missing).
Yee, I checked it out, you're right, the "button" is threaded. Thanks for the heads up, I'll look into it :)