Domestic High Arm Fiddlebase: What are the extra holes for?

I'm having tons of fun with a Domestic high arm fiddlebase treadle that I picked up for $35.  I had been wanting something like this to play with, where I could do whatever the heck I pleased without guilt.  You will see what I am talking about later.  Perhaps much later---I never know how long these things will take.

So here's the quick question:  What are the extra holes in the wooden top for?
There are holes for the treadle belt.
There is a hole corresponding to a hole in the front center of the machine that I think is for a bolt to secure the machine down. It is drilled all the way through
There are holes for the bonnet top (sometimes called "coffin top", ewww).  Projections on the bonnet top slide into the holes to keep it in place.  These holes are in metal.
There are holes for the pins or projections on the bottom of the machine to rest in.  This keeps the machine firmly in place.

However there are a set of extra holes.  These are drilled about halfway through the top, and were filled with what looked like bathtub caulk.  On top of each one was a felt pad, each one secured to the wooden top by the tiniest pins I have ever seen.

The holes for the machine pins (small bumps on the bottom of the machine) are identical to the mystery holes.  They are the same size and also drilled about halfway down into the wood.  Because I stupidly did not take "before" pictures, I can't swear as to whether they also had the caulk and the felt.  

I "get" the felt pads, which would cushion the machine, protect the wooden top, and probably cut down on noise and vibration.  What I don't "get" are the caulk-filled holes.

Any ideas, o brilliant ones among you?

Mysteries of Antique Quilts

Are you intrigued by the mysteries presented by antique quilts?  It is so much fun trying to discover as much as we can about each quilt that comes our way.

Heidi brought over a quilt from her husband's family and we studied it together.   It has a tag on it showing that it had been documented in the North Carolina Quilt Project in 1985.  It is in remarkably good shape for a quilt of its vintage, which Heidi estimates is around or shortly after the turn of the 20th century. 

It appears to have been hand pieced and partially hand appliqued in a Hawaiian pattern, with the usual echo quilting around the motifs very nicely done.  In fact, almost everything about this quilt has been very nicely done.  And herein lies the mystery.

There is no quilting at all in the interior of the motifs, which of course is a reasonable design decision.  But as I studied the quilt I noticed that the edges of the motifs were sewn by machine, and to a much lower standard of quality than the rest of the quilt.  I've seen this kind of thing before, and I leaped to the conclusion that this quilt had been repaired.  Perhaps the fabric of the motifs had frayed and someone later sewed new cloth down over them.

But no, I was wrong.  Flipped the quilt to the back side and saw that there was no evidence of machine stitching.  Those motif edges were sewn down by machine BEFORE the quilt was quilted.

Back to the front side for a closer look, and I noticed that the innermost portions of the motifs had all been appliqued by hand.  And the pattern was the same for each of the large blocks:  innermost edges all hand appliqued (and very nicely, like the rest of the quilt), outer edges all sewn by machine (and with much less skill).  By innermost edges I mean the central star and the linear features radiating outward from it.

So what happened?  Did the quilter get sick of all that hand applique and give up? 

This would mean that she was working on all of the blocks at the same time and had all of the innermost edges of ALL of the blocks done before giving up.  Does this make sense?  Not to me, but then I don't applique.  What do you think?

Did she suddenly receive a nice new sewing machine?   Same objection as above, with an additional objection:  if she got a sewing machine and decided to use it to finish up that applique work, then why would she piece the blocks together by hand? 

I'm sure some quilters continued to piece by hand even after they got that nifty new treadle, but most were quite willing to jump on the sewing machine bandwagon and piece the blocks on the machine.  Perhaps they might continue to piece small blocks by hand for the fun and portability of it, but these are giant blocks.

Ah, mysteries, mysteries.  Heidi and I had fun studying her antique family quilt and I hope you have enjoyed it too.  If you see any clues we missed or have any deductions or guesses of your own, I hope you will leave a comment below.