Remington typewriter

Extremely heavy, thrust-action Remington Rand "quiet-writer" typewriter. Unusual short advance bar in front above keys; atypical green, plastic square keys (not encircled); high support behind platen; unusual metal clip on center of top above typebars; ribbon is loose  and winds on spool attached to typewriter. Tag on front says Penn Jersey Business Machine Company, Morrisville, PA (no zipcode). Unable to locate serial number or model number. Back has writing that says "Remington Rand" and something that is illegible, behind platen has writing that is worn off. Similar to Remington Rand Superwriter, but some features are different. Many small knobs and handles for adjustments, not sure what they do. Much too heavy to be portable, so no case.