This tool is made from light blue rubber and is 6cm tall.  The black plastic aligner contains eight equally spaced holes on one side (for B7G or B8G valves) and and ten on the other (for B9A valves).  By pushing the valve pins gently in, one could ensure that they aligned evenly.

Additionally the rubber base is hollow so can be used to wrap over a glass miniature valve, thereby allowing good grip for extraction of the valve.  A handy hole at the top to loop some string no doubt stopped these tools wandering off the work-bench.