I kinda screwed up my thinking I could mount a fender mirror to the door and actually be able to see what's behind me. It really doesn't work. The screw spacing is 1 7\8 inches. What other mirror can I use? I like the elegant look of the fender mirror can't seem to find a replacement.

 

From my experience it is difficult to find a door mirror that works like a modern mirror due to the front quarter light glass. If you set the mirror up so you can see you then can't open the quarter light. When you move the mirror so the quarter light opens the chrome bar is in the way. I have learnt to live with the latter (the mirror was already positioned here at point of purchase) moving my body and head to see rather than just my eyes. That said I use the door mirror less in the Jaguar than I do in my family car down to the very poor quality of view it gives. Even reversing is difficult using the mirror and the wing mirrors are just for show.
As I understand it door and wing mirrors were never fitted by the factory and were a extra that could be purchased and fitted by the garage at the point of sale.

 

assuming the MK-2 and S type front doors are somewhat similar, your mirror was installed too low.

My S type came with a Lucas "motorcycle" mirror like the one shown in the blue MK-2 picture above, but a lot higher on the upper edge of the door as in the picture of the white S type above.
And there was no interference with the sidelight at all.

But I removed it because I wanted the powered mirrors of the Jaguar XJ-6.

I did a lot of measuring with sidelight open in all its positions to check for any interference until I found the perfect level position for the XJ-6 mirrors.

To cover the oval mounting area and screw holes of the old Lucas mirror, I went to a trophy shop and they cut me an oval cover in brushed stainless steel complete with screw holes using the old Lucas base as a template. I used the original rubber gasket for the new cover.

There is nothing like remote-controlled rearview door mirrors especially if you drive your car in today's traffic and more especially at night when you have another car behind you with its bright lights on.

Yes I know this mod is not for everyone but it is for me.
**I also added a rear top center XJ-6 brake lamp but that's another day, another dollar story. Saul of British Autowood liked it so much, he did it to his 420. I supplied him the XJ-6 brake lamp.
​​​​​​

 

I think the series XJ mirrors that Jose has adopted look good on the S type and 420 and are an excellent option. I taped one up on the door of my Mk2 and for me it seemed a bit too square and modern looking. When I was living in the US 30 years ago, I saw a Chevy that had more oval shaped mirrors that I thought might work. I'd imagined there would be something similar from GM in Europe but haven't found it. In fact, I've not found anything that looks right to me and is as effective as modern mirrors. For the quarter lights, I've never opened them apart from cleaning (once in half a century) and am happy to sacrifice the whole opening mechanism. My best idea is either bullet type (the sort usually attached to fenders), but their diameter is much less than the width of modern mirrors or to try to make something. If I'm not opening the quarter light, why not attach the mirror to the glass? Another possibility that I've probably mentioned before is rear view cameras attached to the doors, though it would be necessary to find space for the video display screens inside the car.

 

Peter,
the 1980-1987 Series 3 XJ-6 electric mirrors and toggle switch were "borrowed" by Jaguar from American Motors of the 1970's.
They match the rectangular front windscreen trim and interior rearview mirror shape.
As you said, they look "proper" in the S type and MK-2.