Thanks Temur. 

I am new to Odoo and I made the following steps as I have done before to find the view form.

In developer mode, I open a product record, choose "manage views" from the debug dropdown and product.product_template_only_form_view  is the external ID of the one that is selected (I assume that if the radio button is selected then it is the correct view I should be taken). The rest listed seem to be inherited from other modules, tree or kanban views. Not sure what I need to be looking at here to check higher priority.

When I check fields list_price(settings>>data structures) it is under this view: product.product_template_form_view. When I change my xml file to match this, again it is the same. No error, no fields. My two new fields are listed under module product.product. 

The other form I can see is product.product_normal_form_view that has list_price on it. Tried this and got following error:

'<field name="list_price">' cannot be located in parent view

Changed the field to lst_price as this was an alternative name (public price not sale price) and my fields now show up on Product Variant view but not product view. 

Really not sure what I need to here to make this work.

If you add field in developers mode, appears ?

If yes, then check in what view it shows this field and add correct view name in xml