California Datsun and my experience

This is regarding a recent purchase from California Datsun. I bought a polished alternator for a late model 1974 260z. I called and ordered it specifically as the owner AL that I had spoken to a few weeks prior to placing the order told me to do as he would send out the one that fits my car to be dissembled and polished. Well I never received a receipt only a email saying I would be contacted when the unit was done and being sent to me. A few weeks later I was told it was done and on the way. 

Problem one. The fan belt I had on my old alternator (Hitachi) did not fit. Nor did one I ordered for that was meant for a 74 260z. I had to measure and order one that fit- it took me several to find one. I called and told Al from California Datsun saying I did not think it was the right alternator for the car. He said that was not the case and never heard anyone that had a problem with the fan belt fitting. Fast forward a few weeks as I had to keep trying different belts until I found one that fit. I installed the alternator and hooked up the battery and it immediately fried the fusable link. Now since I reinstalled the old alternator the car has run a brand new optima battery down and a new auto zone battery. The multi meter has the alternator charging at about 12.75, well below where it should be. So either the damage from the alternator that California Datsun sold me fried the voltage regulator or some other things. BTW- I cannot find a voltage regulator for this car Z motorsports has them on back order and has for months. I tried to post this under comments on the California Datsun web site but the comments seems to be controlled by California Datsun- so there are no negative comments and rather there are comments posted to contradict negative comments posted on other sites- such as this site. So the purpose of this post is...we all work hard on our classic Z's. No one needs to install parts that are bad that damage our cars- possibly to the point of not being able to be repaired either due to lack of replacement parts or possible damage beyond our skill levels. BTW -there has been negative comments posted on this site in the past, also my local Datsun club had some special comments regarding California Datsun none of them good. Just wanted to share my experience so no one else damages their car with bad parts from California Datsun