Unfortunately this didn't work for me. Making the code changes listed above broke the script file.
I've come up with the following solution.
Add a class to the input element that forces the align left. This will overwrite the "style" element set by the InputMask componant:
Add Style Class on the element
"form-control alignLeft"
Style sheet CSS:
/* InputMaskCurrency */
.alignLeft, .form-control.alignLeft {
text-align: left !important;
}