Yes, it is still valid for 1 cents worth of postage. Note that the year indicates the date of the Omnibus, not of the stamp. Scott # 1897 was issued in 1981.
1c 1 cent
This is Scott #1897. This stamp is not from 1880s, that is when the omnibus that is pictured is from. It was issued 100 years later in the 1980's and has a minimal value and can be purchased for 15 cents. A dealer isn't going to want to purchase just one.
It costs 25 cents or $4.75 depending on what stamp it is. Hope this was helpful
Stamp
The stamp has to be accepted where you mail the letter. If you are mailing in Canada, you need a Canadian stamp. If you are in the US mailing to Canada, you can use a US stamp.
1 cent.
A Postage Stamp.
1 stamp (whatever the current price of a stamp is)
The orientation of the stamp is not a factor in mailing. It doesn't matter.
No, you use the postage of the country where you are mailing the item.
It is 32 cents.
A collector might purchase them. But note that this is not from the 1800's. The stamp was issued in 1981.