Include product id in email order confirmation

I am a newbie. I paid a "website" person (WB) to put a purchased template with Zen Cart. I have 1.3.0V. I asked WB to download Security Patch, but was told to do it myself.
My PHP is V4.4.4 and My SQL 4.1.22std (I don't know if this is relevant). As far as I know I do not have add-ons. Ny website is not yet published as I have two problems, one of which follows:

The problem is I need the Product ID that is generated at the end of the listing process, to appear on the Email Order Confirmation. The reason is that although my products are each unique, they often have exactly the same description, and the same price (e.g. earrings) and I can't identify what particular item has been sold.

I can find my way to email_template_checkout.html, but don't know what to insert, and where. And, is this the right place to make the addition?

Thank you
Denise