However there are some small issues with the main slide; it drags a little between 1st and 3rd position-check it after a good clean, and there is a brown sticky deposit on the top of the outer slide when you moved from slide closed. This deposit also runs down the inner slide for a short distance.
Any suggestions about this last part?

What sort of slide bumpers might be in there, rubber, leather, sponge, chocolate sauce?

Thanks in anticipation.
Cheers
Stewbones43