There's three classes of Stuff that Charley can develop in her lab:

1) tech that exists in the real world in 1973,

2) advanced tech that is being developed in the TL 7+1 laboratories of and associated with Project SANDMAN, and

3) wild tech with actual kewl powerz that address/are directed at confronting the Anunnakku and their servants.

Luckily, Category 1 is covered by GURPS High-Tech. Category 2 is going to be much more of a case-by-case judgment; my thought has been since I conceived of the game setting and year that SANDMAN has tech about 10 years in advance of the outside world. And Charley has High TL! So she can develop stuff like this. But again, I'll need to set appropriate Complexity ratings for it and so forth.

As far as Category 3 is concerned, most of which will fall under Charley's various Psychotronics skills, this will also be case-by-case but I would encourage Mel to check out the tech pages of the Madness Dossier setting book (as well as the page about what SANDMAN tech is available in 1973) and extrapolate from there if an idea for an expressly psychotronic piece of equipment strikes you. We can then figure out from the GURPS invention rules how one might develop special equipment like that.

So take Xanten's tones and Zeb's music. I'm treating Xanten's tones as Psychotronic tech. And I'm actually treating Zeb's music (i.e., the ZEBULUN Tapes) as a Reality Shard. What's the difference? Well, Xanten managed to independently strike upon how the Anunnakku millennia ago fucked with our brains to make us receptive to glyphs, neurolinguistic programming, etc. and found a somewhat weak sonic application of said control. Whereas Zeb (we believe, anyway) is from History B and therefore his songs, now on a piece of History A electronic media in the form of reel-to-reel tapes, are essentially artifacts from the other world and as such have unexpected and unclassifiable powers. As we saw in Charley's little prelude appearance at Altamont, her Machine Empathy actually does work on Reality Shards, as long as they can be classified as, well, machines. So yes to the Altamont Object, yes to the ZEBULUN Tapes.

But, say, a mystical sword stuck in a stone in Glastonbury that somehow came over from History B? That's not something Charley would know what to do with.

So what I'm trying to say is that

a) with enough time and money, the sky's the limit for what Charley wants to develop, as long as it's roughly equivalent to mid-'80s technology and/or a piece of psychotronics that works within the logic of the Madness Dossier universe, and

b) Charley will be occasionally useful when it comes to analyzing Anunnaki tech/reality shards/other physical object Weirdnesses.