It is quite apparent that James Beck only features in the exterior location filmwork. This was shot before he was taken (ultimately fatally) ill, hence his absence from the interiors videotaped in the studio at a later date.
In addition to appearing as Private Walker in Dad's Army, James Beck starred as the eponymous Romany Jones in the first two series of the ITV sitcom from 1972. Following his death in 1973 a further two series were produced featuring a new character called Jeremy Crichton-Jones. He was played by Jonathan Cecil who had appeared in this, James Beck's final Dad's Army story, as Captain Cadbury.
The final episode to feature James Beck. The actor passed away before he could film any of his studio scenes for the above installment, after having completed the location footage. His death in August 1973 would cast a slight shadow over the remainder of "Dad's Army."
The final episode to NOT feature Bill Pertwee as warden Hodges; following the death of James beck the antagonistic warden was featured in every episode (along with several other characters) to make up for his absence
The heraldic tabard worn by Private Pike bear the arms of Richard Neville, 5th Earl of Salisbury, who was father to Warwick "The Kingmaker".