My CB350F came into my possession in the fall of 2005 really cosmetically beautiful, including original 4-4 pipes.
Someone along the way, however, managed to strip plenty of screws and bolts that I have slowly discovered during the required maintanence intervals. Not to mention it was sold to me as "running" which it did for about a month, but then completely fouled out the plugs, billowed smoke, backfired, blew a fuse and gave me a nice intro to motorcycle mechanics to get it ready for springtime.
One bodger was the clutch adjustment screw on the right case cover...he snapped half of the adjuster off so it wouldn't take a screw driver. Also, he managed to strip the fork drain bolts and "remedied" them with teflon tape.
When I drained/refilled the forks, I took all the gummy tape off, and now the left fork drain weeps (drips) fork fluid. need to replace that little 6x8 screw. hopefully home depot/lowes has a replacement otherwise it is $1.00 plus $9.00 s/h from ServiceHonda.
When I rebuilt the front master cylinder and caliper, like many of you I found some gum-like rubbery red crap smeared all over the back of the brake pad and piston face. yuck! I cleaned that up and now the brake is pretty darn good, considering 35 year old rubber hoses. I can lock it at low speeds in my dusty, concrete surfaced parking garage.
The last bit of buggery were the rear shocks. these things were shot from the beginning. the would compress, and not return to original unless on the center stand for hours. It made it seem like I was riding a hard tail bike and every philly pothole/ road imperfection would rattle a tooth loose in my jaw. I replaced with a $50 pair of OEM shocks off a 350 twin and the ride is amazingly better, as well as seat height/ corner response is back to normal.
Not nearly as bad as some stories, but, with a 30+ year old bike there is always something.
Oh the stories Tvag or 736cc could tell...