Yup - that's a Leica III(c or d?) designed by the incredibly famous Oskar Barnack - the so called Barnack cameras. Come on guys and gals - where've been been for the past 5 years?! Leica vintage cameras outstripped digital sales and film is sexy once again. Oops. Not at all true. The last bit that is
What do you want to know about your camera? It isn't a 'I' and it's not a II. There are two windows; on the user side: the one on the left is for focussing (an image + a ghost image which you align to get the focus). Your viewfinder is for a normal perspective only. I.e. 50mm. Just like your Summitar f2 lens. It isn't the latest lens; it came after the Summar, and before the Summicron. It's a good lens for its era, but not the sharpest by any stretch. In the history of photographic giants, Zeiss Ikon and Voigtlander produced some of the best interwar lenses before Leica ever caught up.
It's a nice camera, but don't get too excited. These sell for around $300-$600 depending on condition and lens but why would you want to sell it if grandma gave you the heirloom? Look what happened to Esau when he sold his heritage - his nose grew hairs, unlike Pinnochios. Hey! My nose is growing longer just like Barry Manilows! It's still growing as I type! Bad dream, eh?!
Ok. The business. Here's what your dials do. On the top plate from left to right;
The one with a knob and an arrow is your rewind knob. Knobs were better than piddly levers; Barnack designed great knobs. You'll get a handful of knobs with this camera and no piddly levers. The slide under the knob is for your film tension. Beside your number No. 474837 you have a flash bulb mount. This isn't synched to your camera - you need to check if your camera has a little socket for a flash lead on the side. Flash bulbs are a great way to look cool. The chicks loved Barnack for that reason. Guys...just loved his cameras which were great for fondling. Thus the era of the 'Leica fondler' - just about every guy who owned a camera in post-war Wehrmacht yearned to have his German made Leica I or II camera. The British were distraught; Leica wouldn't export to them because they were in middle of a war, and Hitler invaded Poland. So they made a Leica copy (enter the era of the Leica copies.....Corfield Periflexes...and later Russian clones like FEDs, Zorkis etc etc etc!).
Back to your knobs. The knob with the numbers 25, 50, 100, 200, 500 is your main shutter speed selector. It goes from 1/25th second - 1/1000th second + B(ulb) setting. You can get the slower shutter speeds by setting 1/25th sec. and selecting a lower speed on the FRONT dial with the numbers 2, 5, 10, 15, 25 (1/2sec, 1/5th sec, 1/10th sec, 1/25th sec).
The 'R' lever is your rewind button. Don't ever rewind film without pulling the lever up. If you do, you've had it and will rip your film inside the camera. Why is that so bad? Because your camera loads from the bottom up (like all good things German). You'll struggle to get the shredded film out without damaging it.
The far right, you have nationalism, nazism which should be stamped out. On your Barnack, none of these exist. There is a numerical dial from 1-39? for exposures. You set it manually by rotating it to zero when you start.
Ta da! Easy, huh?
Enjoy loading film...that's the fun bit
"Haha, she got it checked out and everything is in perfect working order. He said it should be in a museum."
Which?
Ok - tongue out of cheek. Thank your grandma and don't put it in a leather case: those original Leica cases are so old their straps just snap easily and then the camera drops to the ground and incurs a big dent.
Enjoy your gift.