All the models currently on the beta site are from the original repository, with the exception of the wind turbine (which is used to test animation support). The original models are 4, 35 and 38.
We have discussed including an Overpass Turbo link on the model page to make it easy to find all the locations where this model is used in OSM. 
We plan to convert the existing content once the code is ready to go on the main site. @Ayush_Dhar_Dubey has already looked into suitable tooling and performed a successful test run of the conversion script. This also means that any model IDs on the beta server should be considered temporary.