I have slightly diff to you:
HEI then O from 14a, I from 15a, LTIHRCNC nothing from 37 or 38, N from 39a, ARY
From the downs : RBNTPNV, then L 10d, AEOE then T from 25d then E from 33a
Using these letters in your grid, read from L to R and down etc & hopefully you will be able to see 2 more works by AM and his thematic occasion (google his dates if you haven't got his thematic occasion).
(In the reading of the letters the letters of the 2 works & the thematic occ are all in the right order but interspersed in the grid.)
Hope I haven't confused you even more!