Darn you!! You had to go and bring in Squirrelmort, the bane of good guys, and nut farmers, everywhwere.
The various vignettes were quite enjoyable; it's good to see Harry's team pushing ahead and working together. I'm not enough of a computer tech to know what Harry did wrong (I'm a user, not a tech, I use them to design aircraft and other aerospace vehicles), but I'm certain Tracey will figure it out and I reckon Harry will be embarrassed at his error but proud of Tracey for finding it.
Sirius and Tony make quite a pair and I can see that whole situation encouraging Sirius to consider moving to the United States. Be amusing to read the Daily Bugle's headlines on Sirius' antics.
Beyond that, it's good to see that your muse encouraged another chapter of this one; muses can be very, very fickle creatures and seemingly love to take long vacations in far away climes.