How do I get the most out of limited time?

Greetings, I just read the post initiated by Matthias and got a lot out of it. so that answered some of my questions relating to the breaststroke aspect of my training, but my question is directed more at overall conditioning with limited time. I'm 3 years into Masters (M 40-44). and at one point I was working out with the team and logging 4,000 + a day. Now, (numerous months later) my schedule, job, kids, etc. dictates that I only get an average of 45 min- 1hr in the pool each day (but I do get in 5 days a week). 200 *** is my best event so that is my focus, but I'm trying to increase my conditioning with Free sets. (I just attended a meet this weekend and or course I'm slipping. so I was less than pleased.) I've been reading articles online about Aerobic and Anaerobic training and it's difficult to tailor something just for me. I'm just trying to get a better handle on what my approach should be given my schedule (and being self-coached). Any suggestions on how my weekly schedule M-F should be laid-out. % Free vs % *** ? Mix aerobic/anaerobic 80% 20% in the same w/o and then flip-flop the next day ? Alternate days...all aerobic one day all anaerobic the next? (sample w/o's or links would be welcome as well). Thanks in advance! Bob B