This plane has been repainted and bears the legend "HOT-KTT" short for Hotel Kittilä (KTT is the code for Kittilä airport which is nearby).
There is no serial number visible because the plane has been repainted for advertising. The engine bears words the "Cherokee Arrow"
According to www.planepictures.net
This is OH-PJA, a Piper PA-28R-180 Cherokee Arrow, which crashed on water at Stockholm on 4th August 1979 due to running out of fuel.
There's a photo of it on www.flightforum.fi
in its flightworthy heyday. This site also states that it was the first Arrow to be registered in Finland.