Maybe not exactly Cu-1%Ag alloy, but several alloys designated CuAg or similar.
Several wrought alloys from Europe designated 'CuAg' but << 1% Ag:
Cu-Ag [Netherlands] Symbol: Cu-Ag Standard NEN-ISO 431 Cu+Ag: 99.9
Cu-Ag [International] Symbol: Cu-Ag Standard ISO 431 : 1981 Cu+Ag: 99.9
CuAg [Germany] Number 2.1202 Standard [[DIN 17666 : 1964 bis 1970]] Ag 0.025-0.25 (others, 0.1).
CuAg [Poland] Number MS Standard PN / H-87053 : 1979 contains 0.045-0.25% Ag, (others, 0.1).
Also, 'Cu-Ag-1 [Great Britain]' Number C101 Standard BS 6017 : 1981 contains 0.01-0.027% Ag.
Crosslisted to UNS C11300 which has properties available for many different tempers; e.g., see
Several American Cu casting alloys have 1 wt% Ag (actual range 0.75-1.25%) but also other strengthening elements which reduce conductivity. Used in the heat-treated (precipitation hardened) condition. Normally used for resistance welding electrode tips & electrical switches.
UNS C81700: Ag 1, Be 0.4, Co 0.9,Cu 94.25 (min), Ni 0.9.
Similar is UNS C81800: Ag 1, Be 0.4, Co 1.5, Cu 95.6 (min). Mechanical properties about 10% stronger than for C81700, but elongation is less: 3% (min). vs. 5% (min).
%IACS = 48%.
Some high-conductivity (100%IACS) American copper alloys (C10700, C10940, C11600) given in ASTM B152 & B187 contain 0.085% Ag (min). These are available in a wide range of tempers, with YS from 69 to 310 MPa in 6 mm thickness. E.g.,
If you can determine the applicable standard and whether 1%Ag, maybe more info.
Some data sources: