The engine would not necessarily have low compression pistons if it was turbocharged. In reality, the majority of turbocharged Hondas have stock pistons, for better or worse. If it does have aftermarket pistons, then the block is probably built and if it is healthy, you lucked out! Of course, it would be making less power than stock, if it is lower compression, but if you add a turbo you're good to go.
The decal and cut injector clips are a giveaway, though. I don't see why anyone would have the decal (or have installed other injectors) unless the car was turbocharged or supercharged.
As a side note, AEM does not make cams (only cam gears), and I've never heard of a crackshaft (is that like a pipe?)

How does it not look original? More importantly...why did you open up the engine? Problems? If you are having issues, I'd get on the dealer as much as you need to, in order for them to make it right. If everything is running fine, then it doesn't necessarily mean anything is screwed.
Doing a compression check may or may not tell you anything about the compression ratio. It depends on the accuracy of your gauge.
Someone probably had it turbocharged and removed it to sell the car. Selling the kit and then the car separately would net them more money, and doesn't mean something really funny was going on.
It turns out my car wasn't quite as advertised, but it's more or less all good in the end.