All depends on what you want. A battle-scarred old wreck with screws and bolts replaced with B&Q best self tappers would, if I had it and thought it could be made serviceable, be treated to more aesthetically pleasing nuts and bolts/screws ... even to the extent of cutting new threads as needed and oil blacking the new screws etc. New piston washer and breech seal as a matter of course plus replacement spring if needed. Action cleared of surface rust and then oiled or, if really in the mood I might self blue it. Stock would be cleaned and polished but if really cosmetically challenged I would consider stripping it and refinishing. This all applies to what might be described as a 'bog standard' rifle that is not rare but provides me with a few hours of enjoyment as a nice rifle appears from the mess. If it is a 'valuable' piece then I would go for an exterior clean up as above but not refinish the stock (apart from a clean) or consider a reblue. I would, however, sort out any internal issues with seals / springs.
Just my take on it ... others might well disagree.
Cheers, Phil