What's the plate say on the backside of the deck? I assume it started out life as a Jr., and enough upgrades went into it to merit a Mk. IV status. The HW-19 were, and are, quite upgradeable.
The Jr. was like $700 new, the Mk. III was $1200 and the Mk. IV was $1800.00. Your buying heavier plinths, platters, upgraded bearings and assorted other stuff as you move up the line on these venerable, well-built, good sounding decks.
I'm not so sure the Scout's that replaced them in the line are all-in-all better - they are easier to build, more modern in appearance and a smaller package (as you've noticed it's a damn large fella' at some 16 x 22" or so - it doesn't fit on my otherwise spacaious top rack oof my steel Target rack).
I paid $800 used (no cartridge) for my Mk. III with Hot-Wired Rega 250 arm(VTA, Expressimo stub and counterweight ...but the arm was botch-wired so it needs an expensive fixin' now. No cartridge with mine...so I'd say you done did good, my man.
I think you got the analog-disease realllll bad now
I think it's just friggin' great that this Circle is so busy nowadays !!!(I think it all coincided with 'lcrim' as co-mod - he's the lucky charm here)