Right off the bat, your age is going to require an ETP. That will be a bit of an uphill battle. Also, if those 16 years of service were as an officer that will also require an ETP since they currently cap it at 8 years of commissioned service.
It’s certainly not impossible but since you’ll require an age and possibly a rank ETP that makes for a significant huddles to overcome. Having stellar test scores, knowing the right people and highlighting your prior experience will help out weigh those ETP(s).
Best of luck though and I hope this helps.