After making slides of canada balsam  in which the tests are protected by supporting the cover slips by small tabs of various diameters and thicknesses, other problems emerged; When near transparency finally emerges, it becomes evident that the tests need to be far cleaner than for dry mounting, so an extra cleaning stage needs to be introduced. The first effort  with hydrogen peroxide might be helping but long term immersion will be needed at the very least.I hope more lucid images will emerge. Please remember to click on the image to make it larger.