I've actually got a Rushden save as well - haven't got quite as far as you, but I'm hanging on in the Championship in the 2015/16 season. How did you get the board to expand your stadium? I'm stuck at 6441 capacity, which means the money isn't coming in, which means I can't afford any kind of transfer budget. I've got a pretty decent squad (certainly by Rushden standards!), but I keep losing out on players because I can't meet wage demands, and the club can't keep up financially to support the growth I've achieved in 5 years.
Rushden are a really fun club to manage though. Great stuff.