As I'm considering the possibility of purchasing a used piano, I'd like to educate myself more about what a tech should be checking when assessing a used/restored piano. Anyone wanna share your knowledge/experience in this regard?

First step - buy a copy of the Piano Book by Larry Fine. This will give you most of the information needed to make an informed choice.
Next step - hire a competent piano technician to evaluate the instrument for you.

I understand it is paramount to hire an independent tech to check out the piano, what I'm asking is what this tech should be checking when he's evalulating the piano.

To be blunt. You have been here looking at my new pianos.
That was great. 5 hours of playing is a record!!!!
Now perhaps you can come back and I will explain the other aspect of my business.
I can show you the different jobs in progress and what to look for when you are shopping around.
I offer this tour to anyone looking for a used piano.
Especially important if your looking for a rebuilt instrument.

The information I can share, my weed out some pianos you may come across and save you the evaluation fees.

Everything.

Rod, first of all, thanks for having me over. Your Walters 190 is on my short list (it's a very nice piano btw), as are a couple of others. I still have some a few more places to check out (which includes used and new pianos). Once I have finalized my short list I'll come back to audition the piano again. (Probably around early April). Please understand that this is a big purchase, and I want to spend some serious time with the piano before making a final decision.

However, I'm not interested in purchasing a used piano and then restored it. I'm only interested in piano that are already restored or likely not needed to be restored (that's the reason why I'm asking the question here as I'll need to hire a tech to inspect it). If you have any of those available I'd be interested to come over to check it out.

structural integrity, overall quality, wear and tear, performance of action and tone, immediate needs for servicing, overall value ...

I understood that so I thought I could show you what you were asking intead of typing it here.

I talk better than I type.

Thanks Rod! Please do when I come over next time. I'll really appreciate it.

Would you mind elaborating a little bit more for wear and tear, action and structural integrity?

For wear and tear, my non-technician mind tells me that the hammers will be looked at, but I'm sure there is much more than that.

I'm not Randy, and neither am I a technician, but items that come to my mind when asked about wear and tear, are the following:

Hammer heads
Buckskins on hammer butts and catchers
Felts on butts and backchecks
Damper felts
Key bushings
Sustain pedal wear
Tight or loose centers
Broken springs

The list is certainly not exhaustive, but is what I can think of now.

I have a two page list of items I check. You should expect a detailed written report.

In reality there are several questions being asked. First there is the question of what to look for in a used piano. Is this a late model used piano from the last 30 years or so, or much newer, maybe 10 years old?

If you are looking at high- end, late model instruments, you might find replacement strings, hammer sets, or cabinet finishes, while the rest of the instrument is intact and in good shape. Or you might find completely original equipment.

Example: I just appraised a Steinway B, new 1997 and a Bosendorfer, new from 1994. Both were in very good shape but in need of complete grand action/keyboard regulation, and cleaning. Also a few chips in the finishes but this is to be expected. The rest of the instruments checked out fine. Usually this is the case with late model pianos.

The criteria for inspection of late model instruments for sale will be different than with a restoration.

For a restored piano is this a vintage restoration? Most of the time when folks use the term “restored piano” what comes to mind are older vintage instruments that have been either partially rebuilt, or restored in some way. These are the instruments where virtually every component would have to be checked over.

But your first task is to find a technician you feel you can trust; someone you can work with over the years, as this seems to be a significant purchase for you. When purchasing an instrument, remember that you are also purchasing the services of a maintenance/warranty person. This will have to be someone who can listen and understand what you require from the instrument, and will be able to describe to you what the instrument can give you and what are its limitations.

Mostly what is involved is the technician checking the structural components for compromise, and then the mechanics for condition and function. Any type of report or assessment will tell you the general overall condition, and what might be coming due for repair, or what requires repair in the immediate future. This will tell you whether or not the instrument in question has been taken care of or neglected.