Cassette Spacers

All -

shimano 7-speed cassette
shimano 105 rear hub (fh 5501)

I'm looking for a set of spacers to proportionally spread the 7 cogs
of the cassette over the space of the cassette body.

Somewhere I had found a webpage showing this information, but now of
course I cannot find it.

I've got a Wheels Mfg aluminum spacer behind the largest cog, but
still the other cogs are spaced very closely together.

Does anybody know where I can obtain such a set of spacers?

Thanks!

Phil