T42, my axes, L to R, are:
Mandolin, arch body, spruce and maple, really nice bright tone. Very fond of it.
Octave mandolin, bottom two courses octave pairs, flatback and top, loud with a sweet sounf up the neck and very jangly low down.
Fiddle, cheap Chinese, owned and played for 48 years
Mandolin, second-hand electro-acoustic (pick up jack through strap button). Bioat keel neck (rounded V cross section) with a very sweet sound, plays very nicely. Flatback and top.
Mandola, cheapo flatback plywood thing, no truss rod (guitar style build), heavy action but a good loud session instrument, and I like it.
Mandolin, very cheap arch top and back, bought as a cheap spare. Heavy action, but what the hell, I won't cry if I sit on it in a pub.