What is this? Indexing plate?

[HandyNotHandsome]

I recently purchased a SB 9a, it came with a bunch of miscellaneous tooling etc. I found this part in the stash, not sure what it is. There are two pieces, both aluminum: a thicker top piece which attaches to a thinner bottom piece using 4 knurled screws. The bottom piece has a set of 24 threaded holes, at 15° intervals, into which the screws go. The top piece has a set of 8, threaded, 3/8-16 (?) numbered holes. Number 1 is in the center, and the remaining 7 are at staggered distances from the center. Photos below, the ruler is marked in inches.

Does anyone know what this is, and how to use it?
(It is possible it has nothing to do with the lathe.)
The gentleman who previously owned the lathe (who is no longer available to answer questions) often used it to turn pens, so that may be a clue - or a red herring.

 

[extropic]

I have no idea about it's intended purpose, but I'll be watching to learn'

I'd like to see a straight on picture of the top piece to better understand the pattern of threaded holes.

 

[Bi11Hudson]

While obviously an "index plate" of some sort, for what is a good question. A check of the angular relationship of the base threaded holes to see if they would break down the 24 hole / 15 degree divisions to smaller divisions might provide some insight.

 

[den-den]

It is a wood turning accessory for doing off-center work on small items. The one I have came with a #2 morse taper to male 3/8'-16 tpi adapter. You can screw the accessory on to that adapter in various positions and index the work via the outer holes.

 

[HandyNotHandsome]

Thanks, den! Looking through my box o' stuff, I do see a morse taper /3/8-16 adapter. But I'm still confused - so I can put the taper in the head/tail stock, and then mount this device on it (either centered, or off-center) -but then how do I mount the work?

Also (and I hope I'm not opening another can of worms here) but this adapter came with a part mounted on it that is 3/8-16 threaded on on end, and the other end has some sort of collet on it, except that the collet center is tapped at something like 1/4-20 and came with a set screw in those threads - do those have anything to do with the device that started this thread, or is this a completely different gizmo?

 

[francist]

Here’s some photos — these look almost identical if not exactly the same. I just did a search for “off-center turning chuck”.

 

[HandyNotHandsome]

Here’s some photos — these look almost identical if not exactly the same. I just did a search for “off-center turning chuck”.

Thanks, francist - I had done some searching, but come up with nothing. Your terms get me what I need to finish researching this. Thanks again!