SEO. How to remove product descriptions from menu but keep them accesible?

[walterlyn]

I have some products in my zen cart site which will be no longer available for purchase. But removing them would be bad for SEO, because they make some traffic from google searches. Is there a way to remove product descriptions from menu catalogs but keep them available by the request, i.e. if someone comes from google they could see description and message saying you could buy something similal HERE instead of "Sorry product not found"?

[swguy]

Why not just set quantity to 0 and configure your store not to allow sales of sold out products?

[walterlyn]

I do so but it isn't very pleasant for customers to see items which they cannot buy.
I think that the solution could be to change something in a database for products and add one custom field like display_not_in_category and change function which calls products in the category list not to display and count products which have that custom field with positive value. But my sql knowledge is very limited.

[bigbadboy]

So you want to keep the product page alive for seo but you don't want the customer to see it?

OK. So I google for a product "tin of beans". A link comes up directing me to your store ... and then what? The page turns into a 404?

Sorry but I just don't get what you are saying.