That's normal. The circuit has been improved over the years and it has been adapted to the (not-longer-) availability of some of the components, i.e. LM13700 vs 13600, Coilcraft SLOT TEN vs TOKO variable inductors, then improved pitch and volume range and field geometry due to a different linearization coil configuration (which induced also some slight changes in the oscillator circuits). The schematic from the theremin.info site is the most up to date, except for the linearization coils and one typo: L14 has to be 22uH...
It's an easy exercise to calculate the optimal R and C values for given components and your requirements for the pitch and volume field if you have really understood how this circuit works and what every single component does therein. In that case, you would immediately understand why it sometimes does not really matter if a capacitor goes to ground or to +12V, remember the keyword "equivalent circuit" from your electronics lessons!
(By the way, the 2x 100uF variant for C10 and C11 is the most stable one and C12-R14-R35-R36-R37 work all together and are responsible for the volume response, thus these allow you to "tail" the latter)
If you do not have that knowledge, you probably should not build a theremin from a schematic but rather go with a pre-fabricated kit.
Or you invest first some time in learning and understanding: Besides many commentaries on the web, some very skilled engineers and me too have posted lots of detailed explanations about the EM Theremin (which later became the Etherwave) and its different sub-circuit variants over the past years here. The search function of these forums is your friend!
And then, there is still the opportunity to use the free circuit simulator LTSpice (available for Windows and Mac) which allows you to draw parts or the whole circuit, varying some component values and running simulations to analyze the impact of these changes.
