Problem: When authority records are import ("Stage MARC records for import"), each authority record is assigned a new record number instead of retaining its original record number as recorded in 001 $a. This links bibliographic records to the wrong authority records, and the only way to restore the original linkage is to manual change biblographic $9 with the new authority record 100 $a; or vice versa. So, for example, Clements, Samuel Langhorne old authority (before migration) #9742 new authority (after migration) #8665 100 1 $a Clements, Samuel Langhorne $e [author] $9 9742 245 10 $a Huckleberry Finn / $cMark Twain. ... The bib. record 100 $9 remains 9742 even though that authority record is now assigned to Shakespeare, William. When clicking on the link in the Huck Finn book, the link finds works by William Shakespeare instead. Enhancement request: Authority records 001 $a retain assigned 001 $a instead of being assigned a new authority record number. I have had limited success with building an authority record's 942 $c from the 100 $a, but a more comprehensive solution is in order.
I'd like that too as an option, although I believe there was a reason we did enforce 001 = auth_id from auth_header table. This means enforcing is not so easy as you'd also have to ensure that the records get imported with an enforced record id in Koha.