You need to store all of the extra rows in the files in your dictionary, not just one of them:
dict1 = {row[0]: row[1:] for row in r}
...
dict2 = {row[0]: row[1:] for row in r}
Then, since the values in the dictionaries are lists, you need to just concatenate the lists together:
w.writerows([[key] + dict1.get(key, []) + dict2.get(key, []) for key in keys])