I looked at Farhans site and found http://www.phonestack.com/farhan/xcvr1.html
In that he says:-
The BF195 transistors can be substituted with any other HF transistor like 2N2222 etc. The 2N3866s are best not subsituted. The circuit works with slight increase in the noise figure if BF195 or equivalents are used in place of 2N3866s in the IF stages. The output power on the transmitter absolutely needs the 2N3866s. Subsituting them with other switching transistors didnt give good performance.
The IRF510 should not be subsituted with any other transistor. The other IRFs, though rated higher, have higher input capacitance which makes them a bad choice for 14MHz operation.
The LM380/LM386 can be subsituted with almost any other audio amplifier. Our first amplifier were Cambridge SoundWorks Sound System. If you turn down the bass, they are an excellent system for the shack. We have tried a TBA180, an LM386, an LM380 and even a glow-bug guitar amp. Feel free to experiment.
However thanks for the component supplier.