What is the difference between MCP and METO? I was reading the Cessna 150H POH earlier today and noticed that the manual mentions something like "Normal cruising is done at 65% to 75% of METO power."

The Cessna 172S POH charts refer to cruising power as "75% MCP."

Given that METO stands for "Maximum Except for Take Off" and MCP stands for "Maximum Cruising Power", are the two terms the same thing or do they have differences?
They're the same indeed. Power settings that are not time limited and can be used continuously. The answer is in the model, Cessna 150 vs. 172.

METO is an outdated term, like reading artificial horizon vs. attitude indicator. You'll also find METO in DC-3 documentation, but not MCP.