HammerGuy - As I said in my post, it's almost as if I, or WE in the vintage gun clan, are predisposed to not like or accept them. I suppose it has something to do with them not being original to the gun, will they affect the "feel" of the gun adversely, the unsightliness of a poorly done job.
All of which are valid reasons, to one degree or another.
I will say, though, that as I get older it's not so much a barrier as before. Case in point, recently I wanted to buy a beautiful Woodward (coincidentally) hammer gun that was sleeved but was too late, it got snagged before I could "sink to the depths" and buy a genuinely sleeved gun.
I also have to add that I've seen sleeve jobs where the joint lines are VERY visible, sometimes made more so purposely as a kind of stab at aesthetic adornment. Such guns are totally unacceptable and would never get a second look from me, much less my wallet.