Evidence for Codex Alexandrinus in Egypt

In a recent article (D. Lincicum, ‘Two Overlooked Greek Manuscripts of 1 Clement’ Vig. Cr. 73 (2019), 241–253) David Lincicum provides evidence that a Greek manuscript of 1 Clement in the National Library of Greece—EBE 1896—is a direct copy from Codex Alexandrinus’ text of 1 Clement, from a point in time prior to its arrival in London in 1627 (because of its association with other texts of Alexandrian provenance). This manuscript ‘offers us an important sighting of a notable Codex before it came to the attention of western scholars’ (p. 253). (It also offers a glimpse of the manuscript before it was trimmed for binding in London—so more text is visible in the heading field of the codex.)

‘Seven times in chains’: 1 Clement 5.6 and the New Testament

In 1 Clement 5.6 we read that Paul had borne chains seven times: ‘After he had been seven times in chains, had been driven into exile, had been stoned, and had preached in the east and in the west, he won the genuine glory for his faith ...’ (M Holmes translation).

A question then is the source of this idea that Paul had been in chains seven times.

J.B. Lightfoot suggests vaguely the possibility of ‘some other source’
H.E. Lona accepts that it must have stood in the pre-1 Clement tradition, adding that it may have had a symbolic significance (Lona, Der erste Clemensbrief, 163, without specifying what that would be)
E. Zeller suggested that the author added captivities in Caesarea and Rome to the five punishments mentioned in 2 Cor 11.24 (Lightfoot notes that 2 Cor 11.24 doesn’t refer to imprisonments!)
J.D. Quinn made the interesting suggestion that this referred to ‘the number of documents which were at his disposal in the Roman church that referred to Paul as imprisoned’. I.e. Acts, 2 Cor, Eph, Phil, Col, Phile, 2 Tim. (‘Seven Times He Wore Chains (I Clem. 5.6)’ JBL 97(1978), 574-576)

I wonder whether it might be sufficient to think of Acts as the primary source for 1 Clement here:

1. Acts 16.23-27: in a prison or jail [fulakh//desmwth/rion] in Philippi, with ta\ desma/; 
2. Acts 21.33: bound with ‘two chains’ [a9lu/sesi dusi/] in Jerusalem 
3. Acts 22.29: looks back to the imprisonment in Jerusalem 
4. Acts 23.18: Paul is described, by a Roman centurion, as ‘the prisoner Paul’ [o9 de/smioj Pau=loj]; 
5. Acts 23.35: Paul imprisoned in Caesarea 
6. Acts 24.23: Paul (still) imprisoned in Caesarea 
7. Acts 28.16, 30: Paul under house arrest in Rome