As your gallery still has the Juicebox branding, your upgrade to Juicebox-Pro has not been successful.
The two most likely reasons for this would be:
(1) You have uploaded the Pro 'jbcore' to an incorrect location on your web server.
(2) You have uploaded the Pro 'jbcore' to the correct location on your web server but the existing Lite 'jbcore' files have not been overwritten.

Check that you are uploading the entire Pro 'jbcore' folder (not just the contents) to your 'wp-content/plugins/wp-juicebox/' directory.
Also, try deleting the existing Lite 'jbcore' folder from your web server ('wp-content/plugins/wp-juicebox/jbcore') before uploading the Pro version in its place.

If your Juicebox-Pro zip file is named 'juicebox_pro_1.4.2.zip', then it is unlikely that the files inside are Lite and not Pro.
You can check that the 'jbcore' folder is Pro by opening the 'jbcore/juicebox.js' file in a plain text editor and having a look at the comments at the top of the file.
If the 'juicebox.js' file is Pro, it will read "Juicebox-Pro 1.4.2" rather than "Juicebox-Lite 1.4.2".

The Pro Options text area is available to both Lite and Pro users (although any Pro Options entered will become active only after the plugin has been upgraded to Juicebox-Pro).

If you want to double-check that the zip file you have is, indeed, the Juicebox-Pro zip file (and that it is also complete and not corrupt), you can check the MD5 and/or SHA1 hashes of the file with a program such as HashCalc (free).

juicebox_pro_1.4.2.zip
MD5: d9b0ea9db1be174e3bea5bb678c7a003
SHA1: 0c550f7ab43fb3a2f03d53ad88a93f7fa5df6cbf

Please don't worry about using up your 5 downloads. If/when your link expires, just fill in this Download Link Request Form to request a new download link. In doing so, you will always have an active link and be able to re-download Juicebox-Pro (or download a new version when it becomes available) if necessary.

The only other reason for still seeing the branding (other than uploading Pro files to an incorrect location or uploading Lite files to the correct location) would be server-side caching, which may be serving up old (Lite) files from a cached location even after replacing the 'jbcore' folder.
Please make sure that you do not have any WordPress caching plugins installed and enabled.

Assuming you can confirm that you do have the Pro 'jbcore' folder (by checking as above), try deleting the existing 'jbcore' folder from your web server ('wp-content/plugins/wp-juicebox/jbcore'). Now, before uploading the Pro version, check your web page. The gallery should no longer display (with the 'jbcore' folder now missing). If the gallery does display, then either you are deleting a secondary 'jbcore' folder from your web server that your gallery is not using (from a location other than 'wp-content/plugins/wp-juicebox/jbcore') or there is some server-side caching happening. If this is the case and you do not have any WordPress caching plugins installed and enabled, then try contacting your web host and ask them if they have any such caching in place that might result in what you are seeing.

Hopefully this will help.

I put back the old plugin and the branding disappears and works as it should however as expected Flickr does not work, however all the pro options work with pictures loaded locally
The old Wordpress plugin with juicebox_pro_1.4.2
With the new plugin and juicebox_pro_1.4.2 it does not work as it normally should and we see the branding and the pro options don't work

Hello Steven

Thank you for your feedback, I agree Caching could have this affect but what dissuades me from accepting this is that when I revert to the old plugin and the new juicebox it works at least for the gallery hosted on my site. if things were cached then this would not be the case and I would see the branding still.

if it would help I can give you access to the site hopefully this would help you

I'm not sure what might have been causing your problem. All versions of WP-Juicebox work with all Pro 'jbcore' folders and, even though there may be bugs in certain versions of WP-Juicebox or Juicebox-Pro, no combination should cause the problem you reported.
However, I'm glad that using the latest version of WP-Juicebox works and seems to have solved your problem.
Thank you for posting back to let me know.

Just to let you know, the new 'assets' folder contains an icon to be displayed in the plugin installer page (only for plugins hosted in the WordPress repository).