This is fixed in MacDraw Pro 1.5
Using HyperCard to open MacDraw 1.9.x documents in MacDraw Pro 1.0v1 does not work.
This command should launch MacDraw Pro and open a MacDraw 1.9.x file named MDdoc:
"Open MDdoc with MacDraw Pro"
Instead, it opens a blank, untitled document.
This command works correctly for all other openable file types. For example:
"Open MW2doc with MacDrawPro"
will open a file named MW2doc into MacDraw Pro, even if this file is an EPSF, TIFF, PICT, MacWrite II or any other openable file.