After baking the cleaned parts I began the assembly, which did not go as smoothly as I expected. I had test-fitted the rings with the guide rods before, but I had to move the outside rings further in than anticipated to fit bolts for fixing their position inside the tube. Also, sliding the assemblies into the thermal shield cans was not as easy as before, because the 8-32 set screws that fix the guide rods are sticking out just a little bit. After a little back and forth I was able to place the cavity mounts in the thermal cans in the correct position.

Using a few alignment helpers I placed the cavity cans side by side on the breadboard, accounting for the significant beam walkoff mentioned in previously. I placed the cavities in their mounts and estimated the breadboard lens positions based on mode calculations. I also made sure the lids for the cans can still be attached without removing the lenses, otherwise the whole careful placement would be ruined.