Is R12 brown,black,red or brown,black,orange?
Is R7 red,violet,orange, or red,violet,brown (orange makes it sound bad)
What are the colors on C6? brown,black,orange? Or is that backwards?
Is C5 100nf like C3?
Are the diodes 1N4002? I don't think this one matters much.
R12 on my Trinitron looks brown,black,orange,gold. R7 is red,violet,red,gold. C5 seems to be printed "104M" which is likely 100nF.
C6 looks brown,black,orange,dark blue(???),grey on pink background material. The ring near grey may be also brown or black or dark violet, but it has a different hue than the given brown and black ring of that component. I have several photos of it, but it is dark and shimmers differently on all of them. It is darker than other such rings and might be simply black and shows a hue due to reflected light by the different angle of the bulged package shape.
I did not examine the diodes; they are hard to see without desoldering and likely plain silicon. On D3 I see "400..." On D4 I see a "2" near the ring and a "4" in the 2nd row. (Strange is that many parts have stray solder blobs on top like when a previous owner had soldered at them too.)
Regard that the volume envelope duration (point where decay falls silent) differs with battery voltage. They are 5x 1.5V, so maximum +7.5V (unpleasantly loud, long decay) but it works well below 5V (shorter decay, noise waveforms a bit weaker?).
There's another handheld that needs netlist sound, Coleco Galaxian. It has a sound effect when an enemy dives down. Kevtris made photos of the PCB but one capacitor is hiding in the photo, and some resistor color bands are hard to see.
It also has a weird "PUT" transistor that I don't think MAME supports.
Is it a sawtooth generator like this, or the other (sine?) oscillator?http://www.incbtech.com/index.php/16-how-they-work/2916-how-diacs-and-puts-work-art397e