1. Dual-wipe sockets hold undersized stuff better unless the spring tension has been ruined by shoving fat pins in there, but you could also solder the crystals to a DIP component header. These can frequently be found through surplus houses for cheap.
2. You could ditch the crystals in favor of oscillators designed to fit into sockets (xtal and driver in a single package). This eliminates the crystal buffer circuitry (R35, R36, R37, R38, R39, R40, Q7, Q8) and could replace the X2 circuit as well. A switchable dual oscillator PCB module could then be made for this socket.
There are companies who make dual programmable oscillators, so you could have any 2 switchable frequencies in a single package, but you have to buy the programmer.
The X2 circuit is phase locked into the X1 circuit's output, so I think I would prefer to leave that as is, since the total cost of parts is relatively cheap and readily available (and it works fine, so at this stage I don't want to introduce any new potential problems). As for using oscillators... that was my original intention, and was seen in the early designs, but then I hit a snag with getting one with the non-standard PAL frequency (3.546894 Mhz). Although no problem with getting one in the standard NTSC colorburst frequency. So in an effort to keep this more or less off the shelf, I went in favor of the crystals, which can be gotten for $1 or less. Bottom line, I'm not looking at making anymore changes to the circuits, and although a cool idea with using a programmable and/or dual frequency oscillator, that is a big departure from what I have going at the present time. Custom spec'ed oscillators are also out of the question when we are talking about buying only one or two of something keeping in mind that this is a DIY board.
And lets face it, it's not like you are going to be able to change the system from PAL to NTSC with the flip of a switch anyway, unless you also have two Antic's and two GTIA's on board. So the convenience of a switched dual frequency oscillator really loses it's advantage when you factor in having to also pop out two 40 pin chips and pop in two new ones to take their place each and every time. Most likely a user will stick to one mode (either PAL or NTSC) on any given XEL, because it sure would be a pain switching chips all the time . I plan on having one XEL as PAL, and another XEL setup as NTSC.
However I do like the idea of using a fragment of a DIP dual leaf socket instead, so I'll have to check that out .