Trouble Recovering iMovie Library from failing hard drive and linking it to iMovie Theater file

Hi. The hard drive on my 2014 iMac running OSX 10.9.5 and iMovie 10.0.5 recently started failing badly and, as my recent backup is not quite current, I am struggling to recover the iMovie Library and associated iMovie Theater.

I've created an external boot drive and tried copying the entire MOVIES folder to a partitioned area on that disk, but the finder is getting hung up on a few of the files.

As such, I've been attempting to patch together a healthy Movies folder from a variety of sources. I've come up with a strategy for doing that, but I'm not entirely sure it passes the sniff test, and I've run into a snag or two, so I wanted to ask for some advice.

My current plan is as follows:

1) Take my one, fairly complete back up of the current MOVIES folder (which contains both the iMovie Library and the associated iMovie Theater file) and copy that to the external drive.

2) Open iMovie while holding down the option key and create a second, NEW library on that same drive. Quit iMovie.

3) Harvest the remaining movies from other sources (including the failing drive) by i) right clicking on the iMovie library of interest, ii) selecting the SHOW PACKAGE CONTENTS command, and iii) copying the individual event folders onto the desktop.

4) Right click on the newly created library (Step 2), select SHOW PACKAGE CONTENTS, and copy the files from Step 3 into that library. Then throw out the files entitled _SYNC_ and CURRENTVERSION.FLEXOLIBRARY. This seems to be required for iMovie to recognize the added files.

5) Hold down the option key and Launch iMovie. Choose the library created in Step 1. After iMovie has launched, go to the menu bar at the top and select FILE > OPEN LIBRARY and select the library created in Step 2. This second library, with the files added in Step 3, then shows in the sidebar on the left of iMovie.

6) Highlight the first event that I want to add to the current library. Go back to the menu bar and select FILE > COPY EVENT TO LIBRARY and select the library created in Step 1. Repeat for all events to be transferred.

7) Once done, go back to the menu bar and select FILE > CLOSE LIBRARY "opened in Step 5".

It looks like this should produce a complete library.

My questions are twofold however:

First, is this a legitimate way to handle the merge? In particular, will steps 3-7 produce a properly functioning library?

Second, I seem to be having some trouble linking back the Theater. Even when I select the backup library (which has not been modified in any way) the program will not show the associated theater files. I've right clicked on that Theater file and can see that the actual files are still in there, but iMovie doesn't see them.

Could somone tell me why that is and how to fix this? I've already tried everything I can think of, including holding down option-command to reset the preferences, but no luck. I can't figure out what makes Theater visible to iMovie.

I'd really like to attach the most recent Theater file from the failing hard drive, which has a few more of the projects in it, but I'll settle for just getting the theater from my backup file to work with it's associated iMovie file.

Thanks in advance for any help you can all give.