First a link to their wiki page

There were only ever two members of the Humblebums at a time. Billy Connolly, better known these days as a comedian and Tam Harvey. Tam was replaced by Gerry Rafferty in 1968/9

They produced three albums, one with Tam and two with Gerry. Regretfully I have only been able to get hold of the Gerry Rafferty albums, The New Humblebums and Open Up The Door

Lets start with Rick Rack, from The New Humblebums

All the Best People Do It from Open Up The Door

Steamboat Row is from Open Up The Door

Also from Open Up The Door Shoeshine Boy!

That’s the Humblebums