There was for many years a Steptoe-like institution in Fountainbridge known by the name Asa Wass & Son.
Asa is a biblical Hebrew name, Wass an ancient Anglo-Norman name.

The Asa Wass that registered the company died in 1898 and is buried in Dean cemetery. Although rather like the gag in Steptoe & Son, he was of a long line of Asa Wasses, so might have actually been the "& Son" painted on the gate.
*His* son was Thomas H. Wass

The 1881 census shows only 12 Wasses in Scotland, all in Midlothian. A northern outpost of a name most common in the East Midlands

The latest census that's online shows little change, except the Scottish Wasses are up to 16 and have all moved north into the Grampians!

The "Mapping Jewish life in Edinburgh" publication by the The Research Network in
Jewish Studies at Edinburgh University lists the Wasses as Jewish. Asa Wass and his family are buried under a Celtic cross but I suppose that might just be fashion!

Unlike the Steptoes though, the Wasses didn't live in their own filth in the yard, they lived a few streets away in quite some style

The big flats at 17 Leamington Terrace commands £4-500k these days, and even the generously sized 1 beds at 22 Viewforth and will set you back about £300k!

Asa Wass left an estate worth about £160k i ln today's money when he died (thanks @missyclaren ). Clearly good money to be made then in rags, skins, bones and metal scrap https://twitter.com/missyclaren/status/1309953413556432900?s=19

Edinburgh had a big glue & gelatine industry nearby at Cox's in Gorgie, and both the Esk and Water of Leith supported a big paper industry who made use of linen rags in their process

The Wass yard was down a pend at 161 Fountainbridge. The box marked W.M. is their weighing machine

The Wass yard ceased trading and was abandoned in the early 1960s, and was a haunt for local children to play in. The whole area was quite run down and was swept away in the early 1970s when Scottish & Newcastle relocated the Fountain Brewery there (from over the road)

There are some photos from the mid-late 60s here; http://www.edinphoto.org.uk/0_B/0_buildings_-_asa_wass_yard.htm

And here is the Wass nag and cart in 1925. I wonder if that's Thomas Wass? (pic from Edinburgh Collected)