As you know, i have been using E6000 glue for some time. However, the producer has reformulated the glue due to regulatory reasons and there is no more E6000 - there is only E6000+. This is not, by any means, the same product and I cannot recommend it. It does not withstand the same forces or stresses as the original. I have had to re-do several repairs and I was looking forward with anxiety any repair that required gluing.
For some time I have been using epoxy 2-component glue. This requires mixing it properly before applying. You consume a lot, and then when you apply it, the layer is thick - in some cases, far too thick, and it cannot work properly (for example, in lower post repairs). I had to redo several repairs due to the excessive thickness.
A customer that is also into modeling referred me to a small German company: SCHWANHEIMER INDUSTRIEKLEBER, and their product Industrial Adhesive no.100. They also recommend a primer for difficult plastics - of which our calculators are made of.
This material hardens immediately under pressure: you apply a layer on just one part (it is extremely fluid so be careful) and then press both parts together. If the parts are from our damned calculator bodies, please use also the primer and let it act for at least 10 seconds before applying the glue.
As the material is very fluid, the layer is very thin, and with a good pressure between the parts, you get a very strong bond, and it looks far cleaner than with previous glues. I am considering trying to fix the domes directly - without using the parts we have developed. Let's see how it works over time and we'll be back here with the results.
These glues are not cheap, but they are consumed sparingly (the layers are thin), and the result has been impeccable for the time being!