150 ton near coastal Master wants Towing endorsement

Let me start with the info I have … I am a 150 ton Master - I was a 200 / 500 itc ton Master but can not find work near coastal . I would like to work on towing vessels but have no documented time on towing vessels . I currently have the following endorsements Unlimited Radar, STCW-95, FCC , TWIC . I spent too much time on 100 ton vessels and uscg dropped the tonnage to 150 tons on my last issue date Oct 2007 . I have 20 yrs experience - all near coastal, with approval to test for 500 ton master . MY QUESTIONS …What is the the best route for me to take to get a towing endorsement ?.. Can I test for a towing endorsement and use the 150 ton master as I work my way up as a steersman / pilot/ mate ? Do I need AB , advanced firefighting or arpa for a 150 or 200 ton towing license ?
Thank You for your time . ibdkaptn

if you haven’t already…you might want to start by “working” your way through the applicable “check lists”??

http://www.uscg.mil/nmc/checklists.asp

also 46cfr10.463-466

http://www.access.gpo.gov/nara/cfr/waisidx_04/46cfr10_04.html

Wow … Thank You SEADAWG ! … very helpful !