99Civic AC Woes

Hello, I've been having lots of trouble recently with the A/C on my 99 Civic EX.
The A/C has not blown particularly COLD in a long time. Earlier this
summer, I had problems with the temperature of the air cycling from the 80s to the 50s then back up to the 80s and then back down.
The dealership told me I had a bad compressor, and I should replace the compressor, clutch, coil. I bought the parts, along with a new dryer and had them installed by a trusted mechanic. He had some problems getting the refridgerant into the system, so it was only blowing in the 50s and 60s consistently.
I got an evacuation and recharge from the dealer this past weekend. Did it bright and early in the AM, and the A/C was blowing in the 40s on the way home. Still does blow in the 40s in the AM before the sun comes up.
But once the sun is up, I have real trouble. In the hot afternoon, the system struggles to get into the 60s. I've tried: -turning off the unit's air recirculation feature (when I first start the car, the internal temp is 120+. I'll use outside, cooler air to start off) -turning the blower fan off from full blast. Not sure why, but that helps it drop a few degrees if it blows slow.
I have a simple digital stick thermometer that I'm measuring with, I just stick it in the vent and it clips on like pen.
Anyone have any thoughts? I hate to just start replacing parts, but I'm sweating my butt off and need to get this taken care of.
Thanks for the advice.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.