ORA-01007: variable not in select list

Oracle hurls ORA-01007 when the columns of our query don't match the target variable.

Line 53 is this line FETCH c2 INTO De_Dub_rec;, so the clue is the projection of the cursor doesn't match the record type.

Your free-text SELECT statement is messily laid out, which makes debugging hard. Let's tidy up the projection:

SELECT S.TRANS_GUID             AS OLD_TRANS_GUID
       , S.DETL_CLMNS_HASH      AS DETL_CLMNS_HASH1 
       , S.KEY_CLMNS_HASH       AS KEY_CLMNS_HASH1
       , S.RX_DSPNSD_DT         AS R_DSPNSD_DT
       , S.SUPPLIER_PHARMACY_CD AS SUPPLIER_PHARMACY_CD1 
FROM ...

Now it becomes easy to see that the column order is different from the type's attribute order:

   TYPE rec_typ IS RECORD    
   (    
      OLD_TRANS_GUID        VARCHAR2 (255),
      R_DSPNSD_DT           DATE,    
      DETL_CLMNS_HASH1      VARCHAR2(255),
      KEY_CLMNS_HASH1       VARCHAR2(255),
      SUPPLIER_PHARMACY_CD1 VARCHAR2(200)       
   );    

So your code is trying to put a string into a date variable (and vice versa, but at least Oracle can cast that).

All of which goes to prove that clear layout is not a silly OCD thing. Discipline in writing code helps us write better code quicker by highlighting obvious errors.