I would be very careful to properly identify the pin out of Q1/Q2 and also verify by testing that it is an N channel JFET. Mistakes in pinout could have 10 V forward biasing the gate to drain or gate to source, with no current limiting (since DC wise, the drain is connected to the supply voltage and the gate is directly grounded); instant smoke. These are old part numbers, Onsemi says the j310 is obsolete, don't know about MPF102. Ebay suppliers often substitute and remark other devices to supply demand for these obsolete parts, perhaps without knowing that their supplier has done that. You could get a bipolar transistor or a MOSFET. Even if its a JFET, it could be a low frequency switching device that isn't RF capable.
In reviewing the circuit design, it is my opinion that neither Q1 or Q2 are at risk of being burnt out if the circuit is properly assembled. It also won't be damaged if the xtal is bad and there is no oscillation or if there is strong oscillation at any frequency. This circuit will probably operate with either 3rd or 5th overtone 100 MHz xtals, the schematic gives no indication which to use. If you have doubts about your 100 MHz xtal, you could substitute a fundamental xtal in the 20 MHz range, which would operate on its 5th overtone or one around 33.3MHz, which would operate on its 3rd overtone. While shorting the xtal, as another commenter tried, probably wouldn't hurt anything, it would be a bit better to substitute a 0.01 uF capacitor to avoid upsetting the bias currents in the two transistor circuits, while still passing the RF signal. L10 and the 22 pF variable, plus stray circuit capacitance, forms a parallel resonant tank circuit that strongly favors the desired oscillation frequency and strongly rejects the fundamental and 5th overtone (in the case of a 3rd overtone xtal) or the fundamental, 3rd and 7th overtone in the case of a 5th overtone xtal. The xtal operates in series mode, which is low impedance at the desired frequency.
