Hi all,
About 10 years ago I was in the same position - 39 years old, looking for a career change to fly, etc, etc. and was the ripe ole age of 41 by the time I had my Froz ATPL...... and was there a queue of airlines at my door?? No

way !!!
But I stuck with it, did the FI thing for a while and eventually got a part time job on a Cheiftain....
Now I have the best job on the world - LHS in a nice shiny biz-jet.
Did my age make any difference?
In training - definately not & in many ways it was an advantage as I had considerably more 'worldy knowledge' than the very young guys
In interviews - Airlines just wern't intereted as my 'experience was not appropreate for my age' (yep - good old illegal agism !) - They wanted the early 20's guys...
In part time taxi work (in a cheiftain) and as an FI my age was seen as an advantage - Customers assume (often wrongly !) that a 40's pilot has more skill and experience than a 20's pilot
In my present job, the same applies - the customers like to see the grey hairs of experience sat up front - it makes then feel more secure....
Overall, the only disadvantage I found is that most major airlines want young guys - perhaps because they are more easily manipulated by the management?
Advantages ? Many - you have a better idea of what the world is about and the customers / passengers believe you have more experience (and therefore abillity) and feel safer with a mature pilot.
Having said all that, the way things are right now, nobody is getting work regardless of age...... but who knows - in a year or two we could all be fighting potential employers off with sticks....