Joel,
I'm not sure you need to call a D* installer just yet. You say your mast is plumb and that you have the mounts tight so we have that done. The next thing you need to check is that your dish cannot move around on its own. I mention this since you stated that the dithering bolts seem to be missing. If they are gone the dish will not stay locked into whatever position you set and you really cannot get a firm setup. If the dish is firm on the mount then we can continue. I will assume that things are OK and we can proceed.
From your zip code you live in La Villa, Texas. According to dishpointer your magnetic azimuth needs to be 182.4 degrees and your elevation needs to be 59.1 degrees. You will need a compass or smartphone app to check the azimuth. If you use a compass be sure to keep it away from the metal arm or the metal will cause your compass reading to be wrong. That is why I really like the Satellite AR smartphone app since it uses GPS sats for the compass (and is not influenced by the metal in the dish).
Next you need to get the elevation set correctly. Take a good look at he photo Chip posted. You need to have the side of the slot lined up with the elevation marks on the front. My slimline dish has a red line on the side of the slot that you have to use. But, if you look closely at Chip's picture you can see how the side of the slot points to the 34 degree mark. You need to have your dish look like that for your 59 degree setting.
You will need an associate to help you with the next step because you need to have someone who can look at the receiver and tell you how the settings vary while you move the dish. You can use cell phones to communicate while you are doing the alignment work.
You need to get to the meter display (Menu>Settings & Help> Settings> Satellite> View Signal Strength). Use the first setting that shows up (Satellite: 101, tuner 1). Click on the Signal Meters button which will bring up the signal meter. This is the display you will use for your dish alignment.
If you have done the first two steps correctly you should see some signal strength on your meter. If you see nothing one of the first two steps have not been done correctly and you need to go back and check them to be sure they are correct.
Assuming that you get some reading, you need to make sure the elevation bolts are snug and the pole bolts are loose enough to allow you to move the dish slowly left and right. You now need to move the dish to the left and note the meter. If it goes down you need to move in the opposite direction. Move it back and forth for the best reading. When you have it at your best reading, tighten the bolts that hold the dish to the pole. Make sure all three are tight. You need to make sure that you will not move the azimuth while you adjust the elevation.
Now you need to loosen the elevation bolts slightly until you can move the dish up and down. Do the same movement watching the meter on the screen for the best signal. When you have that, make sure the bolts are tight on the elevation. You are now done with the hard part.
Now you need to set the skew. The skew setting for your location is 84. You can just set it to that for now and see how things work, or you can change your meter to 99 and rotate the dish around the 84 degree setting to get the best meter reading. When you have the best reading, tighten things down and you should be golden.
I know this sounds like a lot. But, you would be surprised how easy it is once you get into it. If this seems like too much work you can call an installer. But, given that you have watched the videos and seem to be comfortable with moving the dish, I would give it one more try before I gave up.
Just my thoughts,
Bob