Embarrasingly I'm a bit of a neanderthal when uploading photos Watson. Do you have Frith's pictorial book England v Australia? It has about 3 photos of O'Reilly with slips in view. However all are from the bowler's end and I'm suspicious this has the illusory effect on perspective of "compressing" his slips closer to the stumps. The same book has about 3 or 4 photos of Barnes' and its hard to gauge slip distance in them. However one is taken from the keeper's end and gives an idea of the depth of the slips. It is photo 362 at the top left of page 114. It is titled "Minnett cuts Barnes to the boundary"
If a slip stood that far back to a spinner you'd think he was placed there to stop a boundary! As a comparison and beneath the photo is another of Rhodes playing Minnett. Again the only slip looks a fair distance back but seemingly not as far as Barnes' . In his cricinfo profile Minnett is described as fast medium.
Edit: I'll ask my wife if she can upload the photo for me. I'll ask her if she can do a comparative of one showing Tiger.