To update...in his latter 'years' Oakie ate a 1:1 combination of 'Supreme Science Selective' hamster (a monocomponent diet), and Cow & Gate 'My First Muesli' (contains apple, raisins, apricot, banana, prunes, oats, wheat, rice, millet, barley, maize, rye, coconut, hazelnut, multivitamins and calcium), with a tiny little bit of fish oil to keep his joints supple (at age 2+ his coat was vibrant and soft, and he was climbing up the bars of his cage and pulling himself up the tiers without the need for a ladder). He usually got about 1 plastic scoop (20g or so) every other day. Because he loved that muesli so much I always waited until most of the heart-shaped biscuits had gone, as I knew he needed to eat them, because they had everything he needed and were tailored to a hamster's dietary requirements. He had a crafty habit of storing the hearts and eating the muesli on the spot to try and get more muesli sooner, but I would check his bed, and he did eat them - I could see the nibble marks!
P.S. Just to clarify - I always DID provide a ladder! Just in case anyone panics