[Phono-L] A couple of additions/changes to the A-250 study

[Andrew Baron]

"dataplate" changed to "bedplate" on item 5.

5) Tone modulator present?:
NO: Serial #1429
YES: Serial #12033 (dataplate #13417), Serial #12080 (bedplate #5751)

8) Louvres on cabinet as per Amberola 1A?
YES: #158, #161, #171, (unconfirmed)
NO: Serial #1429, #12080, #13417