Wow! 16-years and no one mentioned it. Well, anyone familiar with a Butterworth low-pass filter construction knows which inductor is used, and rookies building the kit by the numbers wouldn't understand the block diagram anyway.
I just built two new kits tonight... the QRP40 and the matching 20-watt linear amp. The new boards are much nicer! I built the 40m TX and RX sets some 15-20 years ago and both still work. But, I've modified the transmitter so much that I wanted a fresh one to start with.
You may not have even been working with Ramsey when I built those things, but the old boards didn't have the first component marking on them! Nary a one! Topside of the PC board was nothing but a blank sea of drilled holes without the first component outline or name. The 40m TX board simply says "Ramsey Electronics QRP TX" on the foil side and that's that! You about needed to print the component layout out on onion skin paper and match it to the board in order to get the components in the right holes! Except that we didn't have printers then... LOL
In those days you had to buy the kits and the enclosures separately. I think my kits were $29 for the transmitter, and $19 for the receiver. The enclosures were $14 if memory serves me. There's a bunch of old kits still out there minus the factory cases.
The DPDT crystal select switch never made contact in one position, so I just replaced it with a shorted-leaded toggle switch
Here's another hint. When I did the QRP40 transmitter kit tonight, installation of crystal is omitted from the construction steps. There is some discussion of crystal theory, but no step to install it. No problem... I just slapped it in, but you know better than I that a lot of novice kit builders would be scratching their heads over a left over part.