You would have to search for an old Chrome 49 installer from some third-party website, which I wouldn't recommend.
A better idea for Vista is to use Firefox or Palemoon. If you need to use Chrome, then you need a newer OS.
Firefox Quantum is the 'new' Firefox with a lot of code improvement, including the move to using WebExtensions API for addson (versus the old XUL addons). it is much newer than ESR< which is currently at v52, whereas Quantum is 57. But Quantum also breaks the old addons that are XUL based....
SanDisk Ultra SDSSDHII-960G-G25 SATA III SSD (System)
Crucial MX100 CT256MX100SSD1 SATA III SSD (User Tree)
2 * Seagate Barracuda 7200.12 ST31000528AS SATA II
Seagate ST1500DL001 7200 RPM SATA II
Intel SSDSA2M080G2GC SATA II SSD
ThermalTake BlackWidow 850W
ThermalTake Level 10 GT
Corsair H100 (CPU) + Air (2 * 210 mm + 3 * 120mm fans)