I had a few days off, and was able to (finally) push ahead with laying track up the Ophir high- and low-lines. That section is the last remaining portion of the mainline to lay, and it's now about half completed. Part of the delay was a lack of funds when I ran out of track, but I finally gathered up and sold a bunch of other stuff on eBay, and freed up some funds to continue.
I ran into another problem though, as I planned the spur at Ophir. The spur comes off the curving mainline just after the high bridge 45-A. I was planning to use a Peco code 75 turnout (as all my other turnouts are), but their only curved turnout has a very side outside radius (60" !!), and I just couldn't make that fit. So, plans now are to use a Walthers #7.5 curved turnout, which has radii of 32" and 28", and should be much more workable. It is code 83, so I'll have to figure out a conversion between the code 75 and 83 at this point; hopefully it won't be too bad.
For the code 75 to 55 transition (I want to use code 55 for sidings and spurs), I discovered that Micro Engineering actually makes a code 70 to 55 transition rail joiner, and I picked up a few. I haven't used them yet, but it looks like they'll work well.
Finally, a friend from an operating group south of Chicago dropped by for a visit, and we chatted about the operational possibilities fo the layout, once the trackwork is further along. I planned for operation from the beginning, but it was great to have someone else look at the layout and confirm that group operations would probably work well. I'm looking forward to that day!