Fixing up Pioneer PL-115 Belt Drive TT

I recently picked up a used Pioneer PL-115 TT. Suggestions on things to clean up and improve? I plan on replacing the belt. It currently has a Pioneer headshell. Suggestions for replacing the cartridge? Does this TT need feet? If so, any recommendations?

When I tested out the TT last night, I found that the pitch of instruments/voice would intermittently sag just a little. Ideas on how to fix?

Thanks in advance for any suggestions.

Make sure it has no gunk and remove it from spindle and platter.
Clean mechanisms, arm bearings and switches with DeOxit spray lubricant. Clean RCA plugs out of tonearm and ground wire.

Thanks czarivey.  Should I add feet?  Suggestions on replacing the cartridge?

Chances are pretty good the motor is sticky from old oil & dust accumulation.  Easy enough to clean with DeOxit then lubricate with a light oil.  Needle Doctor and similar retailers carry oils, belts, cleaners and other parts.  After that's done, check the speed again to make sure it's stable.  Something else could be going on otherwise.

Isolation feet may or may not be necessary depending on where you locate the table, how rigid your floor is and other factors.  I suggest you start with a sorbothane patter mat.  Inexpensive and an easy way to isolate noise.  Use it in place of the stock mat.

If the headshell isn't bent or dented, don't worry about it for now.  The cartridge is probably toast if it's original.  The magnet weakens over time.  Go with an Ortofon 2M Red or similar - reliable, inexpensive and performs above it's price point.  Make sure to take the time to align it properly with a good protractor and set the tracking weight at 1.8 to 2.0 grams.  Replace the cartridge leads, too.

I found the Pro-Ject Strobe-It to be a useful tool.  Has a strobe on one side and a very easy-to-use protractor on the other.  Patience is the key to getting everything working properly with these old tables and is well-rewarded.  

Good luck & happy listening!
Effischer- thanks for all the suggestions!  

Any specific suggestions on what to purchase for
(1) replacing cartridge leads, and
(2) sorbothane patter mat?

Since this is an inexpensive used table that is still running just a touch slow, I'm trying to keep my upgrade budget modest. 

a touch slow is more-likely the result of lower frequency than 60hz.
renewing cartridge leads inexpensively can be done at this website is very poorly designed and it would take a time to make a purchase compared to one-click on ebay.