Prevent missing images from using 404 Not Found template

Hi all. I have a unique problem that Im hoping someone can assist me with because it has me stumped

If a page on our site is removed or moved etc then Opencart sends a 404 response on the old URL, however it is also doing this for missing images. Is it possible for any missing images to return a custom image instead of using the not_found.tpl template?

How would I go about this? I tried using a custom .htaccess file in our "image" folder but it didnt do the trick.

Now Im thinking that I may need to edit seo_url.php but I'm not really sure if I'm even on the right path as image urls aren't seo url's. Where should I be looking in Opencarts code?

We have thousands of broken images, and we have a tool created for cleaning them up in bulk, but currently the tool is crashing our website because it's maxing out our Entry Processes by rerouting every broken image through Opencarts PHP Please help

Using OC 1.5.6.4.

You'll get more options and an easier solution with something like this:

https://www.opencart.com/index.php?rout ... search=301

Or, another way would be to write a quick vqmod to add a custom inage to the not_found.tpl file. You could have any custom image you want on that.