With the new X-Cart Classic version - 4.7.4 - the extra fields information by default is not included with products on products list pages. To have this information included there do the following:
Open config.php file (or config.local.php if exists) and at the end of the file just before the closing php tag (?>) add the following piece of code
$obtain_extra_fields = true;
This will add the extra fields information to products array and you will be able to use it on products list pages to show the necessary values. This should work on all X-Cart Classic version 4.7.4 and newer.