Can Somebody Tell Me What I Broke - Water Temp. Sender?

[bigschuss]

The PO of my 1984 K5 with a 305 had an aftermarket water temp. sender installed. It wasn't working and I was trying to remove it and something broke. Not really sure what my next step is.

This is what it looked like.



When I was trying to loosen the smaller nut that held the sender in place the larger fitting snapped off.






This is what I've got now...but I am not really sure what this is. Is that the remains of the larger adapter that is threaded onto a small fitting on the block?

Thanks in advance for any help.