Unsuccessful lookup population through API

gistfile1.txt

FIRST APPROACH:

      account = {
        attributes: { type: 'Account', referenceId: 'dummy-reference' },
        Name: 'TestingCompany',
        Website: 'http://www.testingwebsite.com',
        BillingPostalCode: '11031',
        AnnualRevenue: '43000',
        CW_Industry__c: { CW_UUID__c: '6b4f1c52-3659-48d9-8dd0-5660ee9c4cfc' },
        CW_Subindustry__c: { CW_UUID__c: '9b825489-7184-4a17-aa99-d886e7bbaae1' },
        CanaryAMS__Business_Structure__c: 'Individual',
        CW_Total_Payroll__c: '192391239',
        CanaryAMS__Year_Established__c: '1993',
        CW_Years_of_Experience__c: '20',
        CanaryAMS__of_FT_Employees__c: '2',
        CanaryAMS__of_PT_Employees__c: '3'
      }

SECOND APPROACH:

        account = {
            attributes: { type: 'Account', referenceId: 'dummy-reference' },
            Name: 'TestingCompany',
            Website: 'http://www.testingwebsite.com',
            BillingPostalCode: '11031',
            AnnualRevenue: '43000',
            Accounts_Industry__r: { CW_UUID__c: '6b4f1c52-3659-48d9-8dd0-5660ee9c4cfc' },
            Accounts_Subindustry__r: { CW_UUID__c: '9b825489-7184-4a17-aa99-d886e7bbaae1' },
            CanaryAMS__Business_Structure__c: 'Individual',
            CW_Total_Payroll__c: '192391239',
            CanaryAMS__Year_Established__c: '1993',
            CW_Years_of_Experience__c: '20',
            CanaryAMS__of_FT_Employees__c: '2',
            CanaryAMS__of_PT_Employees__c: '3'
      }