Thanks for the assist. I was able to change the product_name value by adding it to config.inc.php.
I tested adding the logo line but it didn't change the logo. That's fine as I can replace the image files.
Is there a way of editing the pagetitle more so it doesn't show the Welcome message?
Currently, it shows "ProductTest :: Welcome to ProductTest".
As I didn't want to edit the localization files, I tried editing rcmail_output_json but haven't figure it out yet. I tried removing after $name but it didn't change the site.
$labels['welcome'] = 'Welcome to $product';
$this->command('set_pagetitle', empty($name) ? $title : $name . ' :: ' . $title);