I have lost count of the number of engines I got running that had set for decades without all this hoopla.

But yes, you can preoil thru the sending plug hole, I'd probably drain some from the pan and pump it back in thru the sending unit hole so you don't overfill.

Depending on the grade oil and the temps you might be able to use one of those pump up gallon size garden sprayers as your pressurized oil source.

You might want to think about adding an accumulator so you can easily do this in the future.