I do like HK, and really enjoy shooting my USP in 40S&W.
Unlike DUA, as for collectible ones, so far I only got two HK4s.
The first one came with matching 22LR conversion barrel, I say matching because the test target of the barrel has the same pistol serial number on it. It's dated 1968. The other, test fired in 1975, came with all 4 barrels - 22LR, 6,35Br, 7,65Br and 9mm kurz, including cleaning tools, targets, user manual and a nice letter from HK to previous owner explaining how to install the 22LR barrel. Both models have different variant slide, and the manuals depict the correct one for each.
Included also is a pic of my 1968 Mauser Hsc in top condition.
So, nothing out of this world, but nice to have.
I hope you like them.
I've never seen an HK4 four barrel. I would think that is rare, especially with the HK letter and manuals detailing all configurations (illustrated, no less).
The Mauser is in awesome shape also.
I'm currently focused on an AR platform purchase, or 2, but also have my eye on a HK P9S variant (seeing where it goes). Would like an HK4 eventually.
I need a bigger gun budget!