UB40s Signing Off is home to this track:

Intro:(play twice)
G:-------2----4----2-|
D:--2--33---55---33--|
A:33-----------------|
E:-------------------|

Verse:
G:----------2--552---4--774---2-5---------------22--552---4-444--2-------|
D:--2--55223-------55------533---5----22-55-2033--------5------23-2------|
A:33------------------------------0233-----------------------------2---3-|
E:------------------------------------------------------------------033--|

Basically listen to the track & find the positions,There are many many Riffs for you to 
find!It is what it says a 12 Bar trick(I,IV,V)in the key of C.