I'm planning on installing a radio and speaker into my 52 (and the 51 eventually) sometime soon. In doing some research, I found that the speaker is attached to a bracket that fits over the radio turn dials and is then attached to the inside of the dash. Finding the speaker bracket appears to be almost impossible.
Several years ago I purchased an NOS Radio Adapter Kit and have only now brought myself to the point of opening it. Inside the kit I found the speaker bracket, radio housing support for the rear, antenna bracket, templates for drilling a hole for the antenna and for the housing support bracket, as well as the instructions.
The installed speaker bracket can be seen below (image courtesy of eBay).
The speaker bracket is not available in reproduction and I don't think that many vendors even know about it. Plus, not sure how good of a seller this item would be in a repro market, but I have decided to look into it. I plan on locating a few local facilities that may be able to reproduce the bracket. Once I know whether it could be done and the initial cost, I'll then decide if I should enter the repro parts business with my first product.
It's an ambitious step that may not materialize, but it costs only my time and effort to try.
I've got one of those radio brackets too, but I don't recall there being any special bracket for the speaker when I pulled it off of my parts truck... but then again, its been a while since I did that.
 Ok, I think I misunderstood and assumed that the speaker was the same for the '48-'50 and '51-'52 model years
Hello Mr.Panel man!, I am in dire need of one of those kits that you have pictures of ,,, or just diminsions, you said that you may start fabricating some if the cost was not to bad, Well, just how much can your existing speaker adapter kit be bought for?? If it can be bought ! Thank you first of all for posting those pictures so that I now now exactly how the speaker is attached in my 52 f-1
Update: I received a quote on getting the speaker bracket and radio support bracket reproduced a per the original. The initial cost isn't bad and the first run will be limited to 25 pieces. I'd like to know if there'd be interest from FTE members for these parts before I place the order. I'd prefer to have several or at least half preorders. It would about 1-2 weeks to get a run of 25 made. The new kit will also come with a copy of the instructions.
Since selling is not permitted in this forum, please PM or email me, and I'll provide you with the cost and take your pre-order.
EDIT: Forgot to mention that the speaker bracket will allow you to install a 6x9 speaker in the stock location even if you are not using the original radio.