When all else fails make a custom ring
Some jewelers will sketch a concept for you then create a prototype to see as a wax model. More advanced jewelers will use a computer aided design tool to create an image for you to see on a computer screen. The wax model will demonstrate the fit and accuracy of the wedding ring with your engagement ring. It can also be altered with great ease and without incurring added costs. You should be very careful when choosing a jeweler to make you a custom ring because as with any craft there are skilled experts and there are hacks. There is nothing worse than investing hard earned money on something that is poorly made or that improperly interprets your desires. A good rule of thumb is to ask to see a portfolio of the jewelers work or ask to speak to the goldsmith personally to get a feeling of his aptitude for custom work.