Can I deduct Medicare B premiums and other health insurance premiums ?

I'm a retired federal employee under the older CSRS retirement system. I did, however, pay into Medicare while I was working.  Since I don't get Social Security, I pay my Medicare B premiums quarterly. I also pay into the Federal Employee Health Benefit Program (FEHBP) for supplementary medical insurance and also pay into a long term care insurance program. I'm now working as a private engineering consultant and file a Schedule C-EZ. 

My question:
Can I deduct any/all of these out-of-pocket insurance premiums based on being self-employed? If so, where and how? A possible kicker....my wife is still working, not yet Medicare age, and I could be covered by her employee health insurance as a spouse (I currently am not and have my own FEHBP self-only plan). But maybe I can still deduct the Medicare Part B and long term care?