Which type of transistor?

I'm trying to copy an old transistor theremin...but the transistors are old and the part numbers dont seem to be available anymore.
does anyone know or type of transisters I should use? The ones in the old theremin i want to copy say GA3437 on them. I searched on the web for Texas instruments GA3437 and got no results.

Any help would be great.

Thanks in advance

Hey Dean, i've run across a picture of "Sonic Wave" theremin that uses GA3437. Did you find out about them?