The similarity between the dwarf minions from 
Phantasm, and the Jawas from 
Star Wars was 
entirely coincidence, but it should be noted that both Don Coscarelli and George Lucas drew inspiration from Frank Herbert's 
Dune for their respective films.
Coscarelli makes several 
references to Dune in 
Phantasm, while early iterations of 
Star Wars were more noticeably 
influenced by Dune than the final version.
One of the references to 
Dune that remained in 
Star Wars was the Sandcrawler. However, the 
design by Ralph McQuarrie is completely different from the similarly named vehicle from 
Dune, and was modeled in part after NASA's 
Crawler-transporter vehicles.
Kenner made a radio-controlled version of the Sandcrawler to go along with its 3¾" action figures, which sells for a fortune nowadays. A subsequent 
Hasbro version without the radio-control features was given an exclusive re-release around 2004, and sells for a smaller fortune.
I have one of these later versions, which measures 16" long, and 8" high. It scales out to about 1/100 scale if we go by the commonly given 
dimensions for the Sandcrawler.
However, the Hasbro Sandcrawler doesn't look far off of 1/72 scale when compared to the appearance of the full-scale model that was used for filming.
One of the projects that I hope to accomplish someday is to build an interior, add an opening front ramp, and install lighting in this model.