only the original model 404 swingette from 1968 had the tool rack. strangely, even though the original better floor tool and rack were eliminated on the hoover model 409 in 1971, the penncrest swingettes kept the better floor and rack thru 1973.
im my experience, even the original 404's still having their tool racks is rare. the only one of my swingettes that has it is my 1970 penncrest version. and yes, that rack will fit on any portapower, even a brand new commercial one you can still get new. the never changed the tooling to remove the hole inserts for the rack, after all those decades. even if you can't find an original, you could get 10-gauge steel wire and bend one with pilers and needle nose pliers.