On my way to doing other models, I found a way to estimate independent mixture distribution models in OpenMx by using the undocumented, unsupported, but oh so useful mxRowObjective function. I've attached the R script, its plain text output, and the data. The data is from Zucchini and MacDonald's (2009) text on Hidden Markov Models, and is freely available on the book's website .
I'll add the license information to the script, add the mxCheckCloseEnough, and generally follow the template of the other scripts; then I'll add it to trunk/models/passing.
Any comments or suggestions are welcome.