How curious. I bought one of these as well, though mine is from '64. And I too bought an Helios, NOS from another seller.
But unlike yours, the lens is sharp, even though its got cleaning marks on the front element, and is not the red "P" version, which is supposedly better. And my shutter was dragging badly, wouldn't even complete the cycle on the slower speeds without help.
Since I had bought it mostly out of curiosity, I thought "what the hell, it's built quite crudely... lets see if a crude job will fix it..." So I did the WD-40 trick, although I used Würth "Rost Off!". And, lo and behold, it is within about 1/3 stop across the board! Even the 1/1250, which I fully did not expect. Even the self timer which seems a weak link in these cameras.
Only issue is there seems to be a slight horizontal RF misalignment, not an issue past 6-8m or so. But I'll try to adjust it in the future, I think the problem lies in that someone disassembled the lens mount and focusing assembly, and assembled it back "on the wrong notch", ie. one thread groove too far out, which would also explain the slight wobbliness of it with the lens set at infinity.
The Helios has even better contrast; I'm amazed at the glass. Loads of character.
For your lens, inspect it thoroughly for scratches and/or marks on the outside. I've seen some that were partially disassembled for cleaning and were scratched internally and/or assembled with one of the elements not fully seated, sitting slightly off-center, that kills sharpness very fast.
But looking at pic #1, I'd say it is either a RF alignment issue, or the bayonet mount not being exactly where it should, like mine. You can see that the focus is improving going out the frame on the right.