Keels usually are fastened from the inside, but your boat may be different. It's my belief that keels are usually the last thing put on, so I would doubt your Owens would fall apart without it, but again, I have no specific knowledge of Owens.
Opinion? Don't glass over it unless you really know what you're doing. Too often folks do this to wooden boats and it either ruins them, reduces whatever value they have, and/or complicates restoration at a future date. If it's not done right, pinholes may let water in making everything worse, or it may not adhere to the wood very well, and create bubbles. Don't get me wrong here, I don't hate fiberglass, I have a boat made out of it.
How about some pics? We all love pics!
Good luck.
Frank