Vintage BMW Motorcycle Owners

A few years ago I purchased a 63 R50/2 with a 58 R60 motor for $3500. The bike and motor were in good running shape. I decided to rebuild the engine and with misc other parts I probably have around $7000 invested in the bike and have put about 1000 miles on it since the rebuild. I know that since the numbers don't match chances of me making a profit or even getting my money back are slim. I now have an opportunity to trade the bike for something else worth around $5000. Is this a fair trade or should I keep the bike? Basically what I'm asking is can anyone give me an approximate value on my bike? Thanks for the help!

Your bike looks nice BUT because of the mismatched engine/frame it will never have HUGE collectors value so if the $5,000.00 thing is something that you want I say go for it! Old motorcycles/cars are almost never an "investment" (not a $-one anyway, they do pay in memories though).

Vince