The tracing is needed if you were going to submit the paperwork to the State on your own and not go thru a local tag agency; in such case you would need an inspection mechanic or notary to certify that the tracing you submit to the state is a true and correct tracing. If you go to a tag agent to get the title work done, part of their procedure is to verify the VIN via visual inspection. Under most common circumstances such as a sale between buyer and seller with both present and with all documents in order (title, insurance docs, etc) and showing the same VIN, it would be unusual for a tag agent to actually go outside to look at a VIN. Experienced tag agents in business for a long time know when a deal is right and can pretty much smell a bad deal when it's standing in front of them.
Regarding the previous state's title, since Maryland does not require notarized signatures, PA won't require the seller sig to be notarized. You will of course surrender the Maryland title to the tag agent to be replaced by the title to be issued by PA.
Go to the tag agent with the previous state's title and your PA driver's license. If you don' think you'll be driving the car for a while, you do have the option of doing just the title work by itself and then get tags to drive with later. If you are planning to drive the car sooner than later, proof of insurance (classic car insurance from Grundy, Hagerty, American Collectors [who I use], etc, is generally better suited than just adding the X to your existing policy) will be needed to get license plates and registration to drive on the road. And of course cash or checks to cover title and reg fees, the tag agents fees and the PA sales tax on the sale price of the car. It's very likely the agent won't ask for anything else. DO NOT mention or volunteer any statements about VINs. If you do, the tag agent's radar will activate. In case they ask ON THEIR OWN, have these pics handy on your phone: the VIN tag at the base of the driver's side windshield, AND the VIN stamped into the panel above the battery in the frunk, AND the data plate above the right front tire in the frunk, AND the VIN on the white tag on the driver's door jamb. If for some reason the tag agent is not satisfied with those four pics they have every right to ask to see the car in person. You of course have every right to go to the next tag agent down the road.
