HELP, 1950-1959 Ducati, Rare? worth? model?

i do not know much about this bike except it has Ducati all over the motor, and my dad bought it many many years ago, he thinks it is a 1956 or close to it, i cant find VIN # or any writing on the frame or tank, or anywhere on the bike exept the motor. i would like to know how to have it aprasied if it is worth somthing or how to find out make and model and year. any help would be greatly apreiciated, thanks.

great! I can't attach Pic, please email me if you think you can help, or post your email address and i will send Pics.

ajjohnso@santeecooper.com