F/X question

"The alien ships always reminded me of the ships used in "War of the Worlds". Is it possible the models were 'recycled' to make this film?"

Quite possibly. Both films were directed by Byron Haskin.

Olrik

Here's and appendix note from the book Twenty All-Time Great Science Fiction Films by Kenneth Von Gunden and Stuart H. Stock:

"Al Nozaki, Art Director on War of the Worlds, also worked on RCOM. According to Nozaki, it's possible that drawings based on the War Machines from War of the Worlds were used for the spaceships in RCOM rather than three-dimensional models."

Watching the film, it appears that Mr. Nozaki's recollections may well have been correct: the ships in RCOM (obviously the WOTW machines without the cobra necks and with different coloring) move about the screen but are static, angle-wise. They could easily be - and likely are - animated cardboard cutouts. The ships were not called upon to do much (aside from a few laser blasts) in RCOM, so it seems logical that the FX team would forego the hassle of working with the large, cumbersome models created for WOTW.

So your surmise is half-correct: 'recycled', yes; 'models', no...