Nice job! I'd never have guessed it was your first one.
Three tips: put
FOR IMMEDIATE RELEASE
at the very top (align left), and
###
centered at the very bottom (indicates end - it's a publishing thing), and start the first paragraph with:
City, State, Date -- Gallery Traffic Service would like to announce ....
I'll echo the previous poster's tip to add contact info - here's a template; you can use it at the top one line below the "FOR" line, or at the bottom aboive the ### - up to you:
Contact:
Contact Person Name
Company Name
Telephone Number
Fax Number
Email Address
Web site address