I know the term applies to a lot of products that "They don't make them like they used to." Well I've stumbled upon a used pair of Gaggia items (a Baby and an MDF grinder) both from the early 1990s.
I've been wary of stepping onto the yellow brick road that is espresso preparation, but I've been intrigued by the few truly well-made espresso shots I've had that absolutely curled my beard.
My question is: Are machines made in the 1990's just as viable (or moreso) than a brand new item purchased from costco or the like? And I guess for the purposes of my situation I'm talking about these Gaggia items listed above, but if there are any other brands of machine I might run into that have a large margin of quality change then that is worth mentioning also.
But to get back to the OP's original question: Gaggia has had several internal changes over the years; the Old White Coffee(aka OWC or FOWC), the Orange Baby, the 2-switch Coffee, and a few more that show up less frequently. Basically, every Gaggia since the 2-switch Coffee has had the same internal parts with the exception of OPVs & 3-way valves.
If you get a Gaggia Classic that's 10 years old it will be internally identical to the current production version. If it's not ,it's a simple matter to clean it up and expect it to work like new. If there's anything wrong with it, it's simple (and cheap) to repair anything that may need help.
The great thing about Gaggia's is the user's group that Susan & I started (see link in my sig). We have the best Gaggia gurus there, and whether you want to learn how to use it, repair it, or mod the heck out of it, someone there will help you out.