I\'m really confused. I want to do something that a) seems like it should be pretty simple, and b) other people must do all the time, but I cant find out the best w
I've just tried a brief experiment with TortoiseSVN:
Creating the test repositories
At this stage you will be in the state of having created your local 'branch' in a new repository. The last two steps are all you need for an existing project.
To simulate some changes to the original repo, modify the text file in co1 and commit the changes.
Merging Changes
Now, to create your own working copy, check out rep2 into co2.
We should be ready to try merging from rep1 into co2.
Open the merge dialog for co2 and point it at rep1.
For the 'from' revision select the revision at which you exported your copy (in this case revision 1), or the revision that you last updated your local copy to.
For the 'to' revision select the HEAD or the latest update you want to apply.
Results
This seems to work as expected, with the modifications from rep1 being applied to the working copy of rep2 in co2. These then need to be committed back to your local repository.