Helios!
I don't want to butt-in to a month I'm not going to be around for, but on the Helios.... I've got the 44-2, the 44M and the 44M-4. Purchased in London flea markets for a grand total of $50. The 44-2 is the best by some distance to me, followed by the 44M-4, which has fewer blades - 6 vs.8 - but better coatings and is sharp as hell, but less swirly bokeh. (Edit: the 44-2 is very sharp at the centre too).
The 44-2 is a bit wobbly on the screwmount and the images can glow and sometimes flare like someone has smeared the lens with military tank oil. But it has the great advantage of dual aperture rings at the front; one for setting the f-stop, and the other that allows you to open and shut the blades without changing the f-setting...so you can see your bokeh change infront of your eyes, so to speak. That's a lot of fun. The other 44M and 44M-4 don't have these dual rings.
I hope you use the lens Sandy, it'll be great to see what you make of it. The thing to watch out for is how vibrant and colourful (and saturated) the images are. If they look milky/creamy and not too contrasty around the edges, and maybe smeared with a bit of tank oil to give a glow, then that's what you really get. So many Helios 44-2 images on the web look more vibrant, with wonderful crazy swirly bokeh, but they've had a LOT of PP'ing (the images can take it). Personally, I often PP to accentuate the bokeh as its so interesting. But here is one without stressing the bokeh, taken a few days ago during the March challenge.