301, 404 or noindex?

[sabio]

Hi,

 

I recently migrated from oSC to Prestashop. I've made 301s on most of the urls (to the new products on prestashop) However according to webmaster tool I still got 100 404-pages.

 

As for now, they all end up at a custom PS error page. However, should I redirect them to the start site instead?

 

Or should I make a noindex on the missing sites, or leave it as it is?

 

The old url looks like this, and I cant make a 301 on them as the product is no longer in our shop.

 

 

product_info.php?products_id=64

 

 

Regards,

Oscar