It is quite unlikely that Outlaw had those parts custom made for the amplifier. There are many manufacturers that make similar products and they are available for sale.

I would check some of the electronic parts distributors such as Digi-Key, Allied Electronics, or Newark. They all have electronically searchable catalogs online and take credit card orders. You can probably find something close enough to work.
For example, I found this on Digi-Key:


Steve