Toorians on Magusanus

In researching Hercules Magusanus, I have found several writers citing a Celtic etymology published by Lauran Toorians, "Magusanus and the 'Old Lad': a Case of Germanicised Celtic" (NOWELE 42:13-28, 2003). The Latinized Magusanus (less often Mac-, generally in the dative HERCVLI MAGVSANO) is supposedly borrowed from an oxymoric adjective meaning 'young-old'. I have no access to this paper.

The only applicable Celtic roots which I know of are *makWo- 'male descendant, son, young man' and *seno- 'old'. The only way I can arrive at the Germanic consonantism is by assuming a Q-Celtic compound accented on the connecting vowel (which is not in itself a problem), *makWo'-seno-, borrowed before the Lautverschiebung. The earliest known dedication to H.M. is the one from Ruimel, dated to the first half of the first century CE, well before Tacitus.

In citing Germanic names, Tacitus (like other early authors) gives the connecting vowel of /o/-stems as -o- (Marcomanni, Longobardi); this appears as -a- in Gmc. texts (even Gothic and Runic Norse). The intermediate stage was apparently -e- (Alemanni, Alamanni). He also retains non-initial -e- before non-rhotic consonants, which later appears as -i- (not merely in umlauting position; Segestes against Sigismundus in Ammian, and Venedi against OHG Winida, etc.). Thus I would expect the Latinized Gmc. reflex of the presumed Q-Celtic loan to be *Magosenus, at least at Ruimel. By the late third century *Magesinus or *Magasinus might be expected. But in fact the vocalism is consistently Magusanus/Macusanus.

My hunch is that Magusanus has nothing to do with Celtic, and that Toorians has merely neglected the issue with the vowels in order to create a pseudo-Celtic protoform, but before I nominate her for a Voltaire Award, I would like to know whether she actually did provide an explanation for the vowels. If anyone has read this paper and can inform me, I will appreciate it.

Thanks in advance
DGK