I love cast iron! We have two cast iron pans that are on our stove all the time.
They aren't suppose to be washed with soap (I do occasionally). You are supposed to scrap them out and wash with hot water and then put them back on the stove (turned on low) to dry. When dry, season the pan by wiping it down with a little oil. Seasoning the pan is very important!
I adore cast iron. I think I have uh..... 6 or 8 skillets of different sizes and a big deep covered skillet and those cornbread stick pans and am always looking for more!
Not sure what you mean by ID it, but by function that pot will make you the absolutely best roast you have ever in your life eaten. I had one very similar at one time and I swore I could put a brick in it to roast and the brick would come out fork tender. The spikes on the inside of the lid are to send moisture back down to the contents. You braise in this type of pot which allows the moist heat to do the hard work. Put in your meat, an inch of liquid, throw on your potatoes and onions, put in oven and leave the puppy alone. You know it is done when you can't shoo the folks out of the kitchen anymore.
Best pork roast I have ever had, best pot roast, yum, I'm making myself hungry.
Count your blessings that your pot has its original lid. The lids break more often than the pot does and a replacement lid just isn't the same.