Every once in a while I run across something online I've been in the dark about. Here's Doyushu Space Submarine Oska II which seems to be a moderately modified Stingray model.
I'd say it is quite rare.
Info is quite lacking on the web so far.A release date of the space sub line is listed as early 1970's but my feeling is, based on the artwork style (which is quite Space Battleship Yamato influenced) that it is more likely late 1970's.
Yamato was on air 1974-75-ish so kits would have started showing up and influencing other manufacturers mid 70's.
Fantastic Plastic lists the Andro Tiger which is the first of the Space Submarine series as being released in 1980's.
It also appears to have retained the rubber band powered propeller from the Stingray kit. http://www.qcocastore.top/space-submarine-oska-ii-doyusha-model-kit-p-7613.html&language=en
Their other space sub, Andro Tiger http://jungle-scs.co.jp/sysimg/proimg/titimg2/170/104000002218.jpg is another odd ball piece that seems to be a modified previous model.
The upper nose reminds my of TB2 due to the wrap-around windows but also a bit of the Seaview. So I'm undecided in the base model as of yet.
Based on pics at https://www.cybermodeler.com/special/cult2014/pages/a075.shtml which gives us some different views, I can see SR-71 influences also and the scale of it makes it being a Seaview kind of unlikely.
Sorry the information is so sparse that it is not much help.
Do any other readers know any more?