Is it possible to can lemons in a simple syrup as opposed to using salt?
You can bottle (can) citrus fruit including lemons, but they tend to end up like marmalade

If you want to preserve their current flavour, I would suggest freezing thin slices on a metal tray, and when frozen transfer them to small airtight containers or strong 'zipped' freezer bags

Alternatively you can freeze strips of zest (use a potato peeler) and the juice as ice blocks (small size). Again, store in small airtight containers or strong 'zipped' freezer bags