Need help to find date of manufacture for Coleman Mach AC

[pauluptime]

The Coleman Mach AC unit still works fine on our '79 Sovereign. This AC unit came with the trailer when we bought in 2009, but it's definitely not original.
Being that we're set up on a seasonal site in a cooler part of Ontario means we don't need to run it often, but I still want to keep it in good operation for when we do.

I pulled off the shroud this weekend to give everything a good cleaning, also clearing the two small drip tray openings outside so it would stop leaking condensate inside.

I'd like to determine the actual age of this unit and searched all over incl. RVP's site for the manufacture date.
It's Model No: 8333B676 Serial No: 030320427.
Could it be as simple as March 2003 since the s/n starts w/ 0303?

Thanks in advance for any assistance.