Ronda 315 quartz calendar works

[LittleWatchShop]

Unfortunately, I did not take pictures, so I am relying on an ebay picture.  This post is for posterity...not a question.

This watch came to me with a leaky battery.  Corrosion had gotten to the calendar ring, so I had to disassemble the calendar works.

After removing the four screws, the upper plate revealed a lower plate (not shown).  The spring driving the date jumper just jumped out because it is held in position by the second plate which also came loose.  Nothing was lost.  But after cleaning the calendar ring, I was perplexed how to assemble the spring and the lower plate while keeping the date jumper in place and landing four screws!!

Then I realized that the hole cut in the top plate is there to address this very problem.

I assemble the two plates and the date jumper (and other stuff) without the spring.  Once fastened, I inserted the spring into the oblong hole I show outlined in red.  What I thought was an impossible job became trivially easy.