Direct identification with PS *ˀalp- ‘head of large cattle,’ taken for granted in Fox 2003:74, is semantically difficult. An eventual connection with Arb. ˀlf is worth considering (Kogan 2015: 71)
PWS
*ˀaly-at- - fat tail (of a certain race of sheep)
(SED I No. 5)
PWS
*ˀmn - to be true, trustworthy; to have trust
(DRS 23, Marrassini 1971:80‒82, Kogan 2015:72)