[CurlyDave]

Resistors and capacitors manufactured to within plus or minus .0002% are not exactly easy to come by. Commercial stuff is plus or minus 5%, and military spec stuff is plus or minus 2%.

Sorry, but this can easily be accomplished. Purchase a large enough lot and do it by selection of matched components rather than by manufacture to a particular spec.

[blackdog]

I used to make stuff for the industry. The problem is the performance at temperatures and under pressures over time.

I used to match components as part of the building spec process. Quite the paper trail too. I used to do the hot oil immersion, nitrogen dip, impact tables, shock & vibe, and so on......

Perfect matching is easy on the bench, but not so in a variable environment.

I used to custom wind my own metalized film capacitors for just this reason.

[steve-b]

Purchase a large enough lot and do it by selection of matched components

That won't get you components that stay within the fine tolerance over time, under different temperatures and pressures, etc.