Hello All...
Now that my ribbon reversal problem is solved, I have questions on how to set up the Model 15 to operate with MMTTY through the HAL ST-6000. Please contact me if you are using this equipment configuration. 
I am able to copy text from the MMTTY program using what the HAL manual refers to as the "low-tone set" with a mark frequency of 1275. Not sure if that will work on HAM frequencies. Still I haven't conquered sending to the MMTTY from the teletype. 
Thanks in advance for your experienced help.
Bob...