With regard to the question of repairing 27" Regina (or any) discs,
I don't advise trying to replace any of the projections that may have
been broken off.  I've seen it done and when I get such a disc in stock,
I usually bend it in half and discard it.

One of the biggest problems is that 'most of the time' such repairs are
not accurate as to the height and width of the replacement projection.
This can cause damage to the star wheels and binding or snapping of the
disc.

Some of the replacements I've seen involve a tab that has been put
through the projection-less hole and soldered.  If these happen to fall
where the pressure arm roller holds the disc down, it could cause the
projections to be pushed down too far by the pressure roller and could
conceivably cause damage (over time) to the roller itself.

With regard to a discography for the 27" discs, I have a list from John
Bishop (1982), not all inclusive, but of all the titles he could find
at the time.  It's on the wide old pin-fed printer paper and I am happy
to have it copied (I'd have to do it at a professional printer as my
copier isn't wide enough) and send it for whatever the printer charges
and the postage.

Happy Holidays to all!

Nancy Fratti - Nancy Fratti Music Boxes
Canastota, New York, USA
http://www.nancyfrattimusicboxes.com/