Welcome to TBN, Aarchy. The Economy/Power King tractors were sold in the 1950's, '60's and '70's, I think. You'll most likely find well used ones in need of some TLC, but since they have become collectible, you can also find fully restored ones.
I have seen them for sale at antique farm shows and swap meets and, occasionally, one pops up for sale on Craig's List or in the local classifieds or pennysaver ads around here. Don't know if you'd find many of them directly in the Baltimore area, but if you include the surrounding Maryland, Delaware, Pennsylvania and even Virginia/WV regions in your search, something surely would turn up. There are several currently listed for sale on Ebay, I think.
If you are prepared to invest some time and/or $$$, they can make a very good machine for property maintenance and garden work. They have quite a following and it looks like parts are readily available through Ebay, etc.
Good luck in your search.