Arm rests?

The stiff cardboard-like material in my door probably wouldn't support an armrest. You might want to make sure there is some material backing them up to stiffen up the panel.

How about spraying them with some of that vinyl spray?

Robert, I am planning on using some .060 aluminum sheet cut as big as can fit in the hole of the door, plus gluing the plates to the cardboard. I hope that will be stiff enough.

I had thought about adding arm rests just about the time I first got Pearl on the road.

Lately, I think about how nice they might be to have almost every time I take her out.

That said, I got a couple of nicely shaped arm rests from a Toyota Corona that would also need to be wrapped in the appropriate vinyl but looked to be the right size and shape to fit well.  Just found them while wandering through a junkyard and brought them home.  Never installed them, and probably couldn't find them in the vast nothingness of my shop attic now, anyway.

Why not have arm rests?  Your body expects to have them and it's your car, anyway!

Take walk through a salvage yard with approx measurements, you should be able to find something that will work as well as look good. There are a number of street rod aftermarket arm rests but all probable a bit to big

    Thirty seven years ago while browsing through an auto wrecking yard in Fairfield Connecticut I stumbled upon a 356 coupe owned and raced by Paul Newman (Lime Rock) it had a driver's door arm rest as a replacement for the standard hinged, chromed, door pull.

    I'd never seen such a modification and thought it very clever, and that it would be a good creature comfort on my little coupe too...So I went back a couple of days later with screwdrivers to salvage it, but it had already been crushed into a cube!...Aaah, he who hesitates is lost?    

I installed those several years ago. They work great. I didn't add any additional support.

https://www.speedsterowners.com/clip/200709010088

They look like the Empi ones he reference - they look great.  Chrome stripe looks period correct.

Yeah, those look great, Terry!

Yeah, I suffer with bad shoulders and I needed support for my arm. They really work well.

Here's another pic to show the armrest in relation to the overall interior:

https://www.speedsterowners.com/clip/newwheel002

I bought my armrests on Samba.com for about $90.  Put them in my CMC Replica.  They are original 356 ones. Bought from seller in Germany.  Shipping was cheap.

Thanks Terry that gives me a good idea where to put them.

CAUTION!

 Using arm rests will discourage the "Milner hang the elbow over the door look"~

I am using 1972 and up VW Beetle arm rest, which screw on to nylon pieces, the factory installed in the door metal. But, on the CMC speedster I am putting together, using aluminum panels, painted satin black, then the arm rest also will act as the door pull, based on the original design and purpose of them.  Installed in the speedster using small machine screws and lock nuts to the aluminum panel.  I am not about upholstery in a car, which might see lots of driving in the rain.  Everything on my door , inside and out will be rain proof. 

The early style VW Beetle arm rest, shown in the post and EMPI products, for use on the 1957 to 1970 Beetles, has to engage with a metal support.  On the back side of the factory old style arm rest is a metal piece, which is held to the arm rest with two special designed washers and nuts.  The center of that metal piece slides over a metal piece, which is hard to describe.  Like a flat hook, welded inside the Beetle metal door panel.  I see no way to reproduce or replicate that needed flat metal hook inside the door on the fiberglass speedster.  Perhaps, as someone suggested, if you place an aluminum metal plate behind the door panel and then bolt the arm rest to it, that will give you good enough support.  I am not sure how strong that attachment might be. 

The doors are light weight and close easily, so you don't need much force to close the door, but resting your heavy arm ( 50 pounds on some people with them leaning towards the door) requires some solid and secure support.  My use and installation of the 1972 and up VW Beetle door arm rest bolted to the aluminum panel offers the support I want on my speedster.  Just sharing ideas. 

If anyone is interested, I have the early style original VW arm rest, which they show for sale with CMC reproductions and I think EMPI, for sale.  Only have one excellent condition pair, with the original hardware and mounting piece, which fits on the back side of this arm rest.  No chrome piece, as that was only on the early , early arm rest.  Sell for only $30 for the pair, plus shipping, which should not be over $13 for a flat rate USPS box.  I have this advertised on the samba web site, under george4888 user name.