Welcome to the forum. Yes we do have a member who has one of these vessels, which is currently a bare hull - a long-term project which at the moment is on hold - here in New Zealand. The owner is an experienced sailer and also experienced with junk rig conversions, leaving me in no doubt that your little boat would convert nicely to junk rig. A lovely little boat of the "Falmouth Quay Punt" hull shape.
You will get plenty of help on this forum. Also, if you go to (Members' Area) "Directories" you will be able to search for the vessel Sweet Thursday and perhaps make email contact with this fellow Flicka owner, who has sketched up his own proposed junk sail, a fanned cambered type - a little different from the standard Hasler/McLeod type which appears in your link.
(The mast will need to be placed in a position forward of where the the original gaff-rig mast was, as shown on your Sailrite link. These days a variety of junk sail planforms abound, making possible a small range of different mast positions which is sometimes helpful in harmonising with interior arrangements).
PS I found these lovely CAD drawings on an old BoatDesign.net thread here.

I've also got the original lines, if you need them.
