John,
just before we went to bed last night, I thought about moving the yard back to the front and figured I'd get to it today. That's where I had it back on May 16 when the discussion about the 36" reach came up. I was surprised Mark didn't mention having to reach those cassettes over the other tracks, etc., but it was a new idea, so it probably needed time to sink in. 
As for the size of the cassettes, that's up to Mark. My thought was to add a removable box around the tracks, be it 1 or 2.
I have no problem changing the curves in the corners to O72 because they'd allow more landscaping there and reduce the reach. I'm also thinking about changing the loop on the right side and lower left inside corner to O54, but I'm afraid that might reduce the size of the yard and passing siding too much.
Either way, I thought by now folks would figure out that it's no problem for me to incorporate as many variations as possible, even those I don't think will work. After all, it's not my layout and I'm just trying to help Mark get as much of what he'd like as will fit. Plus I enjoy working with SCARM and trying new configurations. I don't know how many variations I've done, but I'm sure glad we didn't have to do this with paper and pencil.
