Hi,

You can create new custom report as per you need and you can inherit the corresponding method you have specified in question, and give the id of the new report you have given.

Currently,

<report 
    id="action_report_saleorder"
    string="Quotation / Order"
    model="sale.order" 
    report_type="qweb-pdf"
    file="sale.report_saleorder" 
    name="sale.report_saleorder"
    print_report_name="(object.state in ('draft', 'sent') and 'Quotation - %s' % (object.name)) or 'Order - %s' % (object.name)"
/>

this report is called from portal.

Thanks