[speeder]

If it's been in dry storage, (indoors), it will probably take minimal work to put it back in service. Has it been drained of fuel? (Most likely). I'd put a fresh battery and gas in it and fire it up. Change the brake fluid, clean it up and ride it real easy at first to check for leaks, etc. I've owned /5 and /6 BMWs and they're very simple, easy to work on and durable as the day is long.

Definitely keep it forever and just take it out once in a while on a sunny day to connect with pleasant memories of your dad, even if you're not that into the bike itself.