Thanks epluznante for the kind words, it's nice to see that someone else is trying to build an homemade ep too! What is the material that you used for your reeds? And could you post photos of the actions that you put together? Is it a reproduction of the Wurly action or did you came-up with something new? Making action parts is probably the most challenging part of the project, as it's really small and needs to be precisely made. I found that cutting the recesses accurately (in the whippen assembly for example) in which the flanges will fit is the most difficult task, as it was probably made with custom machinery by action parts manufacturer. For now I'm cutting those recesses with the table saw and clean them with chisels and files, but I'm not 100% satisfied with the results as some parts have too much side-to-side play when assembled with the flanges. I still need to try to cut these with a router and a custom jig made for this very purpose.
Ideally these recesses should look like this (I took this image from someone of this forum who 3D-modeled an entire Wurly, hope it's ok):

That could be done with a router and a special plunge bit, but I couldn't find anything like this anywhere, so personnally I'm just cutting them flat and it works ok.
For reeds I had the best results with XC100 spring steel which I bought in 5m roll, it's basically feeler gauge material, and it sounds good even if it's cut quite roughly. Don't hesitate to ask for anything if you need to, I'll be happy to help!
So back to the project, right now I've prepared 12 actions:

I'm actually not sure to use these as I'm not completely happy about how they turned out, I'm might redo some parts again with another method involving a router to cut the whip assembly recesses.
Then I worked on the balance and front rails:

The front rail is quite easy to make, the balance rail is more difficult as there's 3 bevel cuts in the same piece. But it's doable with a table saw, a featherboard and patience.
Then cutting 12 keys:

I'm also not quite sure about my method for making the keyboard, as it turned out to be not perfect at the end, but I'm pretty close. The traditional way of making a keyboard is to glue several boards with the grain running in the width, draw the layout of the keys and mortises on this glue-up, then clamping or nailing the whole keyboard to the keybed with the front and balance rails also attached to the keybed, drill all the holes in the keys and the rails at the same time, and then cutting all keys separately. This way the locations of the pivot pins in the rails are pretty much perfect. I chose to do it differently as I don't have a good way to cut the keys accurately from such a big piece. So I chose to cut each key one by one, and then glue them together (using non-permanent glue) with 1 mm shims between them (and 2 mm between the end of the sharps where they meet the naturals):

Then I positioned the assembled keys in the keybed on top of the rails, and I punched the holes positions into the rails using a 4 mm nail, which is what i'm using as the pins by the way.
Next I removed the keyboard and the rails from the keybed and drilled 3,5 mm holes in the rails, using the divets left in the rails by the previous operation:

And finally placed the keys on the rails, and added keytops to each one of them to lock them in their best positions:

I'm of course simplifying here, I'm not talking about how to cut mortises and gluing felt in the mortises, so if anyone needs informations on that, once again, don't hesitate.
So this method for making the keyboard turned out to be pretty ok but definitely not perfect. A few keys on the right part of the keyboard don't sit completely straight (there's a 1 to 2 mm difference in parallelism from the front rail to the end of the keys for the last 4 keys). But I think I know why: when positioning the assembled keys with shims on top of the rails, I also positioned two scrap pieces as spacers on both sides of the keybed, which also acted as wedges to lock the keyboard in place. These two spacers' width where cut according to my 3d plans at 23 mm, but in reality they didn't fit perfectly on the sides and I had to force them too hard to do so, which had the effect of compressing the keys between them, as wood (and paper shims) have a bit of elasticity in this grain direction. And that probably misplaced a few of the pins locations. I also have to be more careful when punching the pins holes in the rails through the keys, using a self-centering punch tool would be also better than a nail.