Hi Duffer,
I have a 30 coupe I did the conversion on,,, It came with the car if you ordered the rumble seat in late 31,,,It's a nice option,, but it's a big job doing the conversion, especialy on the 30...
A few thing's to consider,,,The package tray on your car should be about 6" wide...It has to be cut down to about 5" or you'll loose seat adjustment..The window wood is different, & has to be replaced on your 30...The window glass is different..The upholstery panel's are different...I found out the hard way when I went to install them. On your's the panel's should be about 19" tall from the tray to the headliner...
On the rolldown version they are about 18"...took me week's to fit the panel's. Good thing they were too tall as I'ed of been "Screwed" if it was the other way around..Thank's to Marco for telling me what was wrong !!!!.
As for not being original,,Technicaly the car (30) could of been upgraded by Ford at the Branch "Shop" like it state's in the service Bulletion...I don't know who would of did it back then,,but it was doable...
If your going to do the conversion, the best way is to order the "kit" & go from there... After I got done,,I really liked the set up,,,A very "Cool" upgrade.....
Good Luck,
Greg out west