OK so ideally you need to create a database with your products in and then set a link on each product page with a querystring, i.e.
www.mysite.com/mywebservice.ashx?prodcode=1
when you send this to the service, the service realises you want to mail details about the product with productCode=1. It will find it and send it.
now that is easier said than done but other than doing a start from scratch it's all your faced with because you have static content.
The other option is to pre-create the HTML emails for each product and save them and then just tell the webservice to send the appropriate pre-created HTML email depending on what product the queryString is informing it with.
Get it?
Boog's.