Highly unlikely but... looking for case back for 1976 Seiko 5 'TV' - 6119-5490

My first 'serious' watch (well, 'serious' for a 14 yr old in 1976) was - and is - a Seiko 5 TV. Like a bozo, this impetuous teenager trusted a friend to 'engrave' the back of my watch. Needless to say it was a total disaster. Thankfully, it's on an area free of factory markings and no one ever saw the mess but me. I would love to bring it back to it's pre-botched condition (I fear buffing it out could make matters worse as the hack job is pretty deep...). The rest of this watch still runs perfectly. Quite astonishingly accurate. If anyone happens to have, or know of a resource where I can find a caseback for this baby, I'd be most grateful.

Michael