945C doesn't sound like a transistor number to me.
In this case you can try leaving of the trailing letter, in this case the c.
Maybe it's 2N945 ?
Did you find it in TORBASE ? Not sure if it was that program, but I remember I once bought a software transistor database in the early 90s while I worked at a Taiwanese computer monitor company and after having searched ALL the transistors that were used in "our" monitors and finding ZERO, I sent it back with a nice note and a demand to get our money back....
There are also apps that promise to provide transistor bases (Dutch electronics magazine Electuur has one f.i.) The thing is that these often only produce the specs of the transistor and not equivalents, and also often pretty limited databases. Plus they cost money....