MXR released the Phase 45 along side the more famous Phase 90 in 1975. The name comes from the number of degrees of the phase shift it's capable of. Some say it's similar in sound to a UniVibe and can be modded into being more of a vibe pedal.
The original units used 2N5952 for the FETs (make sure you match them by the way), but others can be used. I listed 2N5457 in the layout because they're what I have on hand. MPF102, J201, or 2N5458s could also be used. Really, any FET with the DSG pinout.
If you want, you can hardwire the C500k pot to the top of the board, though I would suggest using a long leg PCB mount pot (like these) and mounting it above the component side of the board (like this).