I've swapped to LH now and have shot 3-4 times for a total of around 175 arrows or so. How's it look?

 

shooting my frankenstine ILF bow around 40 lbs at 28" and my new to me Fred Anderson Skookum (I've only put 10 arrows through it!) 50lbs @ 28".

No thoughts??

First question is "how is your shooting?"  Are you satisfied with it or is there a particular thing you're wondering about?

My initial thought, watching you shoot is that you are drawing using your upper (top) of the shoulder muscles rather than your back.  If you watch your elbow as you draw, do you see the generally "upwards" movement compared to your shoulder line?  A suggestion would be (from me) to start with your string arm higher and try to generate a more downwards motion compared  to your shoulder line.  That would put the weight of the bow more into your back muscles than it appears that your are getting now.  This is just a thought and really depends on your answers to the questions a the beginning.

I'm just starting lefty. I'm looking to see what I need to do to build correctly from the ground up. I have hardley shot at all yet, so anything that you see (like you mentioned) would be helpful.

I'll work on drawing with my back more. Any drills to do for that?

If you don't have one, pick up (or make) a form master.  That will teach you good back tension drawing.  Obviously, finding a coach is the best answer but is not always available to all.  If you are just starting, you are doing very good so far.