My contributions to this forum are always addressed also to other people, not only to the O/P. And I found it nice to tell, that such a FET buffer can be built very easily, if the only task is to detect whether the oscillator runs or not. The only purpose of the shown FET buffer is to provide a small enough load capacitance. Professional FET-buffers, which show superior big signal performance, for instance, contain a lot more components, of course, to implement constant current sources, etc.

Richard, I'm not interested to hold the hand of the newby posting here, but to offer him and others a wide field of information, where it's on him to pick out what he needs.
For the most newbies the shown buffer might look confusing. But I'm waiting for the one forum member, for whom the FET buffer is useful information.

Kai