Underwood Typewriter

This is my latest typewriter, and I got it for free. It was advertised on my work website, I didn't see the notice but one of my work colleagues (who knew I was a typewriter nut) told me about it. The man who was giving it away very kindly gave me a lift to the train station and I brought it home on the train. I was very tempted to sit at a table take it out and pretend to do some work, but didn't. I was getting enough funny looks already! I don't know what model it is and am not sure how old it is either. My guess is 1950s at the latest and 1940s at the earliest. Any typewriter geeks out there are welcome to correct me if I'm wrong. I would love to know what model it is, I've thoroughly examined it but can't find a model number anywhere. All it says is - Underwood Made in England . The next step is to get some ribbons for it and get it working. Then I will drive my boyfriend nuts with what he calls "tappety, tap tap tap..." Anyways, I think its beautiful and am absolutely delighted with it.