Most any dishwasher you buy will fit into the same space, so I wouldn't worry too much about that.

Your machine dates to the early/mid 1980s, and is an excellent performer (although these days it helps to seek out detergent with phosphates for use with older machines like yours that have shorter cycle times).

If you don't want to fix whatever may be wrong with it, you might get $50 for it on craigslist.

Ralph