To inherit the sale order report as below:

<template id="report_saleorder_document_inherit_quotation_number" inherit_id="sale.report_saleorder_document">

    <xpath expr="//span[@t-field='doc.name']" position="replace">

        <span t-if="doc.state in ['draft','sent']" t-field="doc.quotation_number"/>

        <span t-else="" t-field="doc.name"/>

    </xpath>

</template>

The customer preview has a template which you can inherit and change it separately as below:

 <template id="portal_my_quotations_inhrit"  inherit_id="sale.portal_my_quotations">

    <xpath expr="//t[@t-out='quotation.name']" position="replace">

        <t t-out="quotation.quotation_number"/>

    </xpath>

 </template>

To inherit the sale order report as below:

```

```

The customer preview has a template which you can inherit and change it separately as below:

```

```