The answer is in Larcade book, Part 1, Page 58.
Helmets of the RIR 109 and LIR 109 wore a reserve cross above the griffons star with its small "Fidelitas" cross. But as Larcade wrote, most of the time the small "Fidelitas" cross was removed, because it could not be seen with the reserve cross above.... The banner of such helmets are also most of the time without the sentence "Mit Gott f. Fuerst u. Vaterland"
By the way, I was visiting a collector friend in northern France, a month ago. We could visit a very small private but fantastic museum in a farm, at Saint Waast, near Arras. An old guy spent his whole life to collect things he found on the Somme battlefields. In one of his display boards, there was a relic of such a scarce RIR or LIR 109 helmet wappen!!! Never saw one before!!
Philippe :salute: