Speaker Remounting
The previous owner had put in MB Quart tweeters on 3 out of 4 speakers and some no name brand on the 4th. He had also gutted the OEM speakers and used the rim of the speaker basket as a mounting braket for the new ones. This technique has been used by others and it seems like it might work if the cutting was done carefully. Mine on the other hand were cut poorly and all but one of the rings had broken over the years and the speaker grill outside rings had all broken so it was time for some cleanup.

I had originally intended to build a mounting base so that I could use the MB Quart grills which I like better than the OEM anyway so with a couple of 3" sewer pipe caps I created the bases below. When it came time to recover the door panels I decided to go with the MB Quart intended mounting directly on the door panel (had to fill in the larger hole first) and only use the sewer pipe adapters for the rear speakers.

This is the sewer pipe cap. The process was fairly easy, cut the cap to about 1/2 inch height, cut hole to fit speaker, drill mounting holes (I like the look of 8 with allen head screws but 4 are all that is needed), smooth top, paint to match interior (could be left natural black if smoothing/sanding job is done carefully), mount using exiting OEM speednuts and a few more if using 8 screws.

The normal mounting of the MB Quart is fine, but the OEM hole in the door panel and vinyl or leather is too large. By recovering the small section at the top of the door panel (only about 1 by 3 foot piece of material) the panel hole can be patched with some aluminum, very thin masonite or plywood, plastic sheet or my choice formica sheet. I don't like to add weight and it does need to be thin, but stiff so would go for aluminum or plastic (plexiglass), but I happened to have some formica left laying around (I used 2 layers to get about 1/8 inch thickness).