Seth Thomas Clock

Hi, I am 48 yrs. old & I have grown up looking at this clock, I now have it in my home. The clock is by Seth Thomas, it has black metal spikes & a brass(?) face. It is 24" x 24". I love the look of it. How can I clean the face? Is it really brass? Approximately how old is it? Any information would be great.

Thanks!!
Kelly