The NIH has several sample annotated applications that may be of use if you can find one for the mechanism of interest. My guess is that the list below will grow with the use of electronic submission.
NIAID Sample R01 and Summary Statement – updated to reflect electronic submission no less (NIAID was the first to post a sample annotated grant application & continues to lead the way in grantsmanship)
NHLBI K02 model applications (one on lung development & vascular biology, the other on fluid flow & vascular adhesion)
NHLBI K23 model applications (one on epidemiology, the other on blood diseases)
CSR Grant Review Process Video & Model Applications (video of mock study section with PDF transcript plus application and summary statements for the R01, K08, and R03 proposals “reviewed” in the mock study section)