Re 121 High Street Eston.
Bulmer's 1890 Directory for Eston has a list of Trades there, some with addresses.
Your photograph shows part of the High Street before the construction of The Square as an "island" for buses, toilets etc. You can see the wall behind the man on the right, which extended to the Institute and was without buildings.
On the extreme left was OSBORNE'S DARPER'S SHOP which was no 69 in 1890. Though the shopowners'names changed over the years, the trade carried out often did not. Being an Eston lad, born in the 1930s, I think that I can identify the following by continuing LEFT around the back of the photographer who took your shot - i.e. towards Gladstone, West , William Streets, past the hospital site to California WHERE PROSPECT TERRACE IS SITUATED:
(Bracketed names apply to the 1930s-1940s)
OSBORNE 69
BUTCHER 71(There is stilla butcher next door)
CONFECTIONER 75 (was Maggie Norman's)
STATIONER 93 (was Patterson's or Pengilly's)
POSTMASTER 105(COMPLETELY SURE OF THIS ONE) (was Stoddart's)
in other words we are heading for your no 121 probably between the hospital site and the bottom of California Bank and PROSPECT TERRACE
( Prospect Terrace contained the homes of the peers of Eston society!)
With a little more time I might be able to pinpoint no 121.
Best Wishes, Ron Kerrison.