I assume many of the younger ladies have age restrictions?  

I've seen 1000's of reviews and provider websites over the years. Only once did I see one that had an age restriction.

I've hobbied exclusively in Chi and haven't had an issue with my age, 64.
When you inquire, let the lady know your age, and ask her if she has an issue with it.
I've stayed with the lovely MILF's for the most part. But the younger gals I've seen have been very accepting.
I prefer 40+. They have the touch and instinctively know how to treat the older gents.
Do your research. Chicago's a wonderful city for playtime.

I'm an old guy too.  Similar experiences and preferences.  The younger ladies are usually very accepting but the more mature ladies tend to be more fun for me.

....if they don't I'd probably assume they don't have any. But if interested in a particular lady I would hope most gents include some basic details about themselves anyways like age and when you do just throw in if your age will be an issue if you're still unsure.
Many who do have a restriction of age typically have a minimum not a maximum.

I totally agree, I am an older fella and enjoy providers over 40.  I just feel more comfortable and at ease and mostly not rushed out the door....

They are rare but always a delight i enjoy