Nazko Sunshine Mill same as Retsel?

First time poster here....I recently bought a Nazko Sunshine Mill off of Ebay for very cheap, missing the hopper but otherwise good condition. My understanding is that Retsel manufactured these for Nazko many years ago, and this mill is identical in looks and quality to the current Mil Rites offered by the Retsel company. During shipping, the on/off switch sheered off, and now I need to replace it. Retsel customer service is telling me I will have to bring the mill in and after 10 days they can let me know if they can service it or not. This seems a bit excessive to me-I just want to order the part and install it myself to save on a trip to their location and money on labor services. If I could find the part myself instead of buying through them I would do that too, but have no idea where to look. Has anyone here installed or replaced one of these on their mills? Is it worth me doing this or should I just take it down to Retsel? Thanks in advance for your help :)

Best,Jocelyn