The replacement tubes that fit into a bottom drain in the livewell come in several diameters and lengths and are generally available in marine stores and of course onlineThe first key measurement is the diameter of the drain. You need to match that to the diameter of the rubber sleeve on he bottom of the stand pipe. Measure accurately, an eight of an inch can make the difference between a good fit and a not so good one. The next detail is the length. Replacement pipes can be shortened by popping off the slotted cap and cutting the tube. As long as the tube fits under the lid, it is OK as a starting point. Often you can guess the height of the tube by seeing if there is an overflow fitting on the side of the livewell. If so, the tube should be a tad lower than that level so that when the tank is filling, water drains into the standing tube before it reaches the side overflow. I am nor sure if your well has a side drain.
Of course, as you mentioned, if someone can measure theirs, that would make things easier but don't forget the diameter of the bushing and drain hole