We know there were two different factory hardtops for MGA roadsters, one aluminum hardtop, and one fiberglass hardtop. There were also more then two dozen aftermarket manufacturers of hardtops for MGA, most of those being fiberglass, a few may be molded plastic, one wood and one steel (that we know about). As far as I know, all of them have drip rails, and in most cases the drip rils will be very similar, because the tops were designed to mate with original factory side curtains. Many of the makers were also likely to use original issue factory hardware, no need to develop anything new, unique or expensive. swo when it comes to finding or making replacement drip rails, it may be that one size fits all (or very close).

On 9/19/2019, Rob McKellar in Wollongong, Australia wrote:
The story begins with with the purchase of my 1500 MGA where an unfinished J&S hard top came with the deal. It has sat in my shed for the last couple of years where it kept calling for me to complete the car. The hardest part of the restoration was the missing drip rails. I have been casually searching the web for a supplier without success.

I also have a MGB where it too has a J&S top which was complete. I thought hard and long when it dawned on me this was a aftermarket manufacturer in the 60's where all the parts to build these tops must have been sourced locally through local suppliers. I started looking through several Aluminum extrusion suppliers web pages showing the 100's of different profiles and there it was clear as day!

Remember those Laminex kitchen tables from the 60's & 70's with that lovely Aluminum edge?

That's it table edge!

So I purchased several 1 meter lengths and started testing how to bend it for the roof curve. I placed a 4 liter paint tin on a nice flat surface, marked the center of the bend and proceeded to create the correct bend for the roof line. The material is very malleable and easy to form to the shape of your top.

I haven't finished fitting the rails but they look the part and will polish up nicely. I have attached some pictures so you can pass this onto anyone interested in restoring their MGA or B top.