The Mac Plus ROMS are the same ROMs used in the 512Ke. The ROMs on the 128K are the same used on the 512K. Since both ROM sets work on the 512K motherboard, they will work on a 128K motherboard. You just have to line the pins up right on the sockets and the high/low ROMs in their respective sockets when you put them in.
As for that bright line on the video - that is an analog board problem. There are many threads on the forum about analog board fixes or start one here. Have a picture of it?
As for that bright line on the video - that is an analog board problem. There are many threads on the forum about analog board fixes or start one here. Have a picture of it?