If you look at all the Allegro threads you'll find mine, which came with Campy hubs, cone dates 58 and 59, so I assume the bike is from about 1960. My serial number is six digits,165167. So if yours has only five digits, I'm going to guess it's quite a bit earlier than 1958, unless Allegro seriously upped their production numbers right around then (which is of course possible).
HI I HAVE AN ALLEGRO BICYCLE 23"SEATTUBE SERIEL
#154107 WAS REPAINTED CAN SEE SOME CHROME ON BACK AXLE I think it's a special what year do you think it's from.thank you..