can anyone recommend a person in LA area to pay to install a tricky Koetsu cartridge

I should add that many good options here if bring tt to a retail store but am looking for home cartridge setup.

This is a good time in history to develop some do it your self skills. Why not look up some videos on YouTube that describe how to install a cartridge? Michael Fremer has several, and I am sure there are others. ( Search for Fremer or Stereophile which may sponsor his videos.) The only thing you will need is a rudimentary tool to set the stylus tip at the right place. There are any number of decent alignment protractors available for well under $100 with which you can do that. Perfection in this process is optional.

I'm with lewm, and will go even further, this is totally one you want to learn to DIY. I would even go so far as to say you never really know what it is to own and properly run a turntable until you do. Cuts right through so much of the mystery when you understand by doing. 

I installed my Koetsu Black Goldline, but I've done several and can tell you there is nothing special about any Koetsu, at least not when it comes to alignment. They are all the same.

Here's what you do. Order the Mobile Fidelity Geo-Disk. https://www.amazon.com/Mobile-Fidelity-Sound-Labs-Geo-Disc/dp/B003WXLG2I There's lots of others, there's even free ones you can download and print. This one has a bunch of features that make it worth the $50 over the freebies. 

Order a stylus force gauge if you don't already have one. Tweezers. Tiny little screwdriver. Scotch tape. Q-tips. Rubber band. Koetsu don't come with much so make sure you have the right size screws and nuts on hand. Visit your local shop. Ask. DO NOT believe any of their BS about how you need anything else not on my list.

Now while you're waiting go watch those Fremer video's. Here's how to watch the videos. DO NOT watch them thinking "I must do exactly every single thing he says" because you do not. Fremer shows a lot of totally unnecessary stuff, because so many guys have bought this stuff and learned how to do all these unnecessary steps and are gonna be offended if Fremer says it was all a waste of time and money. Even though it was. But literally nobody ever spent a couple grand on doo-dads then turned around and said that was dumb they're just doo-dads. Literally never happened. (Listen close, he drops hints here and there that this is in fact the case!) 

Here's the tricks you really want to know. 

Do this on your well lit kitchen table. Give yourself the whole day for this. It will take like 30 minutes. But having the whole day eliminates all stress and makes you feel so smart to be done in less than full day!

Leave the stylus guard on while mounting.

Koetsu uses nuts. It will seem like you need 3 hands. Use the rubber band. Makes it so much easier!

Use Scotch tape to hold the platter and Geo-Disk steady.

You'll be lowering the stylus onto the target grid, raising, adjusting, lowering, repeatedly. A Q-tip laid crosswise will prevent damage in case you spaz out. Brilliant idea, and I thought of it, which even Fremer didn't, Ha! So draw your own conclusions! 

That's it. Koetsu makes it hard with the nuts and not labeling the pins. Oh well. Live and learn. We all do. Next time, Soundsmith. Meantime, no worries, you are in for some fabulous sound.

 

The Koetsu RSP is no harder or easier than any other cartridge install, so if you have any experience in this, don't fret. On the other hand if you have no experience, now would be a good time to get acquainted with the process as those before have noted, albeit that would be one cart you would not want to destroy in a learning process. Enjoy the music