You haven't been looking carefully enough. There are a bunch of CCFs in the file section that will work with that model DSS receiver - including one with the specific model name under the appropriately named "Dish Network" section of the "Pronto" file area.

There should also be no problem learning the original remote with a TSU1000 as a last resort - but as I said there is no shortage of codes/files for this player.

The 301 will work with the same codes as the 501, 508, 510, 511, 522, 701, 921, 6000, 2700, etc...

Bruno