Good pic's Tim.
Bike is back in action - grafted the short cage of the smashed 105 onto the 1988 Deore mech. Nearly new 34t middle ring, nearly new chain, hoping the cassette is ok with them. Weirdly, every chainring bolt was loose - presume the effect of pedalling with way too tight a chain. Also bb has noticeable play in it, probably not related. Bum, don't have any 73mm shell 113 mm UN72's in my well stocked & immaculately organised spares department.