I'm about a month away from a deal on an 8" model 29-2 and a 6" model 28-2. From what I understand the 28 ( Highway Patrolman) is the less glamorous version of the 27.
Yes , the Highway Patrolman ( Later M28 ) was the * Plain * version of the .357 Magnum ( Later M27 ) .
Matte blue instead of high polish blue . No topstrap checkering . 4 and 6 inch only , while the M27 had origonal standard lengths of 3.5 , 5 , 6.5 , 8 3/8 , and every length inbetween as special order . Later , 4 replaced 3.5 , and 6 replaced 6.5 as standardized .
M28 ramp front only , M27 had multiple options ( albeit the Ramp most common ) .
Orgionally the Budget " Working Gun " , in recent years the intrest from both Shooters and Collectors , has M28 prices not far behind the more common variants of M27 .
Added - l have my Father's post war , pre Model Number 5 inch .
I briefly owned & carried a 4 inch M28 , that moved on to my best friend ( RIP) .
It had the unusal combination of being extremely accurate ( 0.75 @ 25 yds ) , but a big cylinder gap ( 0.010 plus , maybe 12 ) . My friend subsequently sent to S&W , and had the Bbl set back .)