replica or original

Does anyone know what the best way is to see if a 45 is a replica or original? Are there any marks or something I could look at?

Do you mean a reissue, or a bootleg?

Ways to tell a bootleg:

- The label has irregularities.
- The matrix number is missing, or does not match the original.
- The sound quality is bad.

Ways to tell a reissue:

- The label is one not in use when the original record was issued (e.g. RCA used a black label in the late 1950s and early 1960s, switched to a yellow-orange label in the mid 1960s, and a red and white label in the mid 70s.)

- The record is a label used for reissues (RCA Camden, RCA Gold Seal, Okeh, Mala, Sphere Sound, Pickwick), or has the word "classic" on it.

- The record is in stereo, and the original recording was made before 1966.

- The flip side is not the flip side listed in the catalogs of original hits.

- The catalog number or matrix number is wrong.

- The recording was remixed.

- For some records made before 1958, a lack of noise in the vertical direction (heard in stereo, but not in mono).