Vintage mandolin & 1926 Martin T-18 tiple

Any information/clues as to the maker of the mandolin would be greatly appreciated! It was given to my husband by his grandfather many years ago -- guessing it's probably 1930s - 1940s vintage, but we don't know. No maker's mark/label anywhere on the mandolin.

The Martin tiple has been dated (through its serial number) to 1926. A representative at the factory told us it probably sold for $40 in 1926.

The original owner told my husband (when passing it down to him some 20 years ago) she was giving it to him on the condition that he not play any rock 'n' roll music on it, because the instrument was "dedicated to the Lord."

Well, we all know how hard it is to resist the urge to rock out on a tiple -- but somehow we have managed to avoid doing so thus far.