That's a groaner.... The trade is close...... Much depends upon the details such as; Is the 28-2 and "S" or an "N" prefixed frame? What kind of condition is the M&P in? Is it a "V" Serial Numbered gun? Is it Polished Blue, Brushed Blue or Parkerized? Is it correct (stocks, lanyard ring and all) and all origional?
Unless the M&P were in Very Good-to-Excellent condition my inclination would be to make the trade I think. The .38 S&W (.38-200) chambered guns don't seem to bring the kind of money the .38 Special guns do....
A 4" "S" Frame 28-2 with Diamonds is heading for $500 maybe a little more if indeed NEW IN BOX. An "N" serialed gun would be about $50 or so less.
Sometimes I forget what a fine revolver those 4" Highway Patrolman revolvers are. I was visiting my dad last week and I got his out to look it over and wipe it down. It isn't NIB, but it's still mighty clean with just a little holster wear. The sales receipt was in the box...I paid $74.95 + tax for it at Carter's in Houston,Tx. in the early 1970s. S&W HPs weren't getting much respect back in those days! :lol:
Here's a photo of my Pop with his HP. He'll be 94 in a few months, but don't try to break into the house.