Creating And Assigning New ID To Duplicate Records

There is currently a database which contains location information on a variety of different samples, each which is identified by a unique sample number (the primary key). However, when these samples are processed, they are split it half and each is assigned a second identifier for each half (in this case, an A or a B). Therefore, if originally there was sample 1, it will be split into 1A and 1B. My task is essentially to create a second database with further information for each sample half (1A or 1B), while maintaining a link to the main sample database to reflect any changes to the sample location information. So far I have been using a make table query that pulls from the linked table which links back to the main database and combines with another table that simply has one column called "Piece" which has an 'A' in the first row and a 'B' in the second row.

I am quite new to using access, but I have found this task fairly frustrating so far because it feels like I am trying to force access to work in ways that it was not designed. Essentially I would like access to create a duplicate entry for each sample in the original database, and force in an 'A' or a 'B', and combine these fields to create a unique identifier. However, I am running into a lot of issue when trying to append data from the original database etc.