I have been given a free 1989 WaveRunner 500. The unit is in great shape - just needed paint and a few other mechanical tweaks. I am tring to complete the new paint after epoxying the cracks and digs in the hull, but am perplexed by an oval hole on the top of the hull, under the seat towards the front. The previous owner had duct tape over the hole - what part belongs here? I cannot find a replacement anywhere on the parts sites. I would like to know what I need to replace! Any help is appreciated!