An interesting question with a surprising answer!

I did a little digging on the web, assuming the name 'tungensis' was spelled wrong or obsolete. It turns out there is a different genus, petopentia, which contains an obsolete species name, tugelensis. This plant is often incorrectly labeled Fockea tugelensis. This genus contains caudiciforms that look like Fockeas, but are not closely related. I think the true name of your plant is likely Petopentia natalensis.

The article linked below is very informative. This is the relevant part for you:

"Plants in cultivation as Fockea tugelensis have proven not to be that species but are actually another caudiciforn not at all closely related and correctly named Petopentia natalensis (Schlechter) Bullock. The plant illustrated in Rowley (1987) as the former is actually this plant. The plant has also been grown under the invalid name Fockea natalensis."

Here is a link that might be useful: FOCKEA, CIBIRHIZA AND PETOPENTIA

Wow - Thanks for the leg-work Para- That link is a good read and much appreciated - I really like the plant, I wish I would have grabbed another one.

Thanks -

Todd