Help indentify please

[paulminus273]

A good friend has inherited a Helios 25-70mm f3.5/3.8 mc auto zoom, number 805773-10.
It looks like m42 pentax fit( not measured) and looks pristine
Does anyone know things like, is it any good and has it got any value
Thank you

 

[RaglanSurf]

It's sounds like a Russian made 70/80's workhorse lens, not particularly common but nothing spectacular and probably not worth a huge amount either. I would have thought £15ish