No need for surgery of the existing lamp. These are industry standard panel indicator lamps to fit a 12mm hole. They are easily available in a wide range of voltages and colors (if green shouldn't be to your taste!)
You can buy them from Amazon for US$7 in any color you might like. For example Amazon item number B01N7XVWTT As you browse for these, the key specifications are they have to fit a 12mm hole, and run on 220V. Be a bit careful, there are similar lamps with a 12mm face diameter that fit a 9mm hole!
Important Note: that 12mm hole spec is from my boat's panel. Double check yours to see it it is the same.
I am sure there are suppliers could get them even cheaper.
It is always useful to remember that Amel didn't have things like this custom made, that would have been extraordinarily expensive--to no benefit. They bought things that were easily available to them at the time. It's always a good idea to search industrial supply chains for these kinds of routine parts, most are still easily available with a bit of google work--once you know what to ask for!