Thanks for sharing the files, I've had a look at the tour.
Single node stereo panoramas (images) are not supported yet in the released version of VR Tourviewer. This will be available in the upcoming update of VR Tourviewer.
The explanation here
with the _tb in filename is only for the use of stereoscopic 360 video, not for images.
The current version of VR Tourviewer supports stereoscopic panoramas created in Pano2VR by using one panorama for each eye:
Ie: node1 is for the left eye of panorama A, node2 is for the right eye panorama A, node3 is for the left eye of panorama B, etc. Then you can add the User Data ‘stereo’ tag and watch your tour in stereo. Note that you have to copy hotspots to the right eye panorama as well and link them to the right eye nodes for them to show up in both eyes.