Some belts turn to goo over time, so I'd open it up as soon as possible before it migrates and gets harder to clean. That's if it is goo. I'd guess .18 - .235 is closer to a typical 8tr belt, 1/4" seems too small for the torque needed. The width is going to be somewhere around 10% less than the space between the flanges on the drive pulley found on the motor shaft. As long is it is narrow enough to fit without hitting the edges of the pulley when running, it's OK, too narrow and it might slip on startup and have more flutter.
The length is just as important, too big will slip, too small will cause speed to drag and premature bearing wear on the motor and flywheel. Did both sites list the same length but different widths?
There was/is a cross reference by model published by PRB, but this model isn't listed.
The next best option is to measure the old one.
The two sites have a different dimension listed, not knowing anything else about them, if one is not quite right, maybe both are. I'd measure it myself or have someone I trust do it.
I can't seem to find a service manual for this model, but if it has an original Panasonic part number, the PRB cross reference might list it.
Also, not to doubt anybody's troubleshooting, but are you sure it needs a belt? what's the symptom?
hope this helps
-j.
