This is the Wrenn "N" Gauge Catalogue No 420 "London Brick Company" Private Owner (PO) Wagon in Red issued by Wrenn/Lima from 1973. Note : this was then issued again in 1976 under Catalogue No 720 with different packaging. 

Comes complete in original Wrenn clear plastic case, including numbered card which forms the profile of the wagon. This approach was later changed across the "N" range to sponge profiles to protect the wagon where clear plastic boxes were used..

Overall Condition is "near mint" for its age.