Hi all,
Working on a theremin using this document (circuit diagram p3, component list p6), and am having a very hard time finding these inductors unless I want to buy them for 5 bucks a piece on ebay... it's a total of 11 so that adds up. Are there viable alternatives to these that are actually still stocked anywhere normal like Mouser? Are there places where I may still be able to get these components? I haven't found any. L1-4 and L7-10 construct antenna coils, so I'm afraid to change the specs of the inductors for fear I'll introduce noise or drastically change the sound of the instrument by using components different than what was called for. When choosing alternative components, I'm not sure which characteristics I can safely change without impacting the antenna coil function too severely.

Linked above, but for convenience:

 

Well it has been more than 16 years since Bourns acquired JW Miller. Drop them a line and see if they can cross those numbers.
https://www.bourns.com/en/news/press-releases/pr/2006/05/01/bourns-acquires-assets-of-j-w-miller-division-of-bell-industries-#:~:text=Bourns Acquires Assets of J.W. Miller Division of,Magnetics Division of Bell Industries, Inc. from Bell.

 

There's a good chance of finding compatible RF chokes in old tube RF equipment (radios, TVs). I wouldn't expect they are critical, mostly just for blocking RF signals. One of the cheap ebay/Ali/Amazon "transistor testers" should be able to measure them.
You might still find inductors on the shelf of surplus dealers or old-school independent electronics parts dealers, if you can find any that are still alive. Or at dealers specializing in parts for antique radio restorers.
As for the variable inductors, there's a discussion here:
http://www.thereminworld.com/Forums/T/26293/toko-inductors-needed-for-em-theremin

 

Take a peek here Antique Radios - The Collector's Resource There are lots of antique electronics sites. When the local distributors and the radio/tv repair shops closed down they sold their remaining stock cheaply and it's still around.