Things are good today, I thought things over and I am actually in good shape. If the old passport doesn't show by Thursday, I can still go to the US Embassy and get a temporary passport. While I am in the States, my old passport will certainly arrive from the Home Office and my wife can bring it to the airport if necessary. That solves the problem of coming back on the temporary passport. I'm sure when I come up to the border agent with all that mess (3 different passports, Home Office Case number, ILR in expired passport, tales of MP involvement) they will just wave me through to avoid the paperwork.