Vintage SABA oval fullrangers?

I just bought a pair of those vintage Saba Oval Greencones Alnico. They are 17cm x 11.5cm. Apart from the classified stating that these are 5 ohms and have the 1678 CU 60 reference printed on the backs, I cannot find any kind of informations about them. I browsed some very old school german website & forums, but still couldn't find anything.

The seller said these were sold as tweeters, but are actually very competent fullrangers. They're made of paper, and the magnet looks pretty big and heavy.

Does anyone have more informations about them? I think they look really cool and would deserve a really beautiful cabinet. Although I'm pretty sure they would need some assistance in the bass region, probably...

Screenshot 2023-08-19 at 21.18.53.png

Screenshot 2023-08-19 at 21.19.07.png
Screenshot 2023-08-19 at 21.19.18.png
 
The T/S parameters will allow you to design a good box, but that is only the low frequency side of the response.
In order to fully evaluate the loudspeakers you will also need to measure their freq. response, distortion, etc.