That was XM330, now at the International helicopter museum.
http://www.helicoptermuseum.co.uk/westland.htm
It was the last flying MK1 and was fitted with an APIN starter. From what I remember there was something odd about that as the MK3's had an airstart system. (I think!).This exploded on startup one day, blew an impressive hole in the nose and grounded it! I was in the last year of my apprenticeship at the time so that puts it about 1982ish
Rgds Dr I