Well, for you and everyone who has issues with .rar archives, here's link to .zip version of same archive: https://mega.nz/file/MAkVSZYL#KYyoMLO2--r7pcsLomVJE-DzPlKxVMUY6GNg3ACV5Rw
As a contributor of that collection (but Archive.org account is not mine), I would say most of SuperMac ROMs there are from 68kmla (I can't say which ones). Just in case, updated version: https://mega.nz/file/IVkxWByb#nhVBWRw18Rz4bWt2-p6tlGR9LQqkC0iF1cUDfmKu7Vs
Yep, that's newer generation, and this model was flagship one. As for implementing support in MAME, at least there are photo of boards on BitSavers.
P.S. How can I see test page? I've failed to use instruction on BeefChicken since I'm using Windows. And do you need ROM for StyleWriter II?
I would like to have more ROMs for Apple printers too (and other manufacturers), but here's ROMs for LaserWriter IIg (downloaded from Bitsavers.org, where they were available for couple days only).