Restrict access to custom post type based on its taxonomy terms

You should be able to check the conditions and add capabilities like this:

if(wp_get_current_user('gallerist') AND 
  'cats' == get_post_type() AND 
  has_term( 'status', 'age' )) {  

$gallerist_role = get_role( 'gallerist' );

// Adding a new capability to role
$gallerist_role->add_cap( 'custom_capability' );
}

I am sorry I can not test it but I think it is a start