This was grouped in with a auction purchase.  It shows no signs of wear and appears to be new in original case.  For more detailed description see below.  It was purchased from MSC and has a MSC part number of 08236861

Specs
Indexable Profiling Toolholders | Internal or External: External | Hand of Holder: Right Hand | Rake: Neutral | Insert Compatibility: NP.. | Toolholder Style: NKLC | Series: Top Notch
Internal or External
External
Hand of Holder
Right Hand
Rake
Neutral
Insert Compatibility
NP..
Toolholder Style
NKLC
Series
Top Notch
Toolholder Material
Steel
Through Coolant (Yes/No)
No
Shank Width/Diameter (mm)
25.40
Shank Height (mm)
25.40
Shank Height (Decimal Inch)
1.0000
Shank Width/Diameter (Decimal Inch)
1.0000
Overall Length (Inch)
5
Overall Length (Decimal Inch)
5.0000
Overall Length (mm)
127.00
Insert Holding Method
Clamp
Lead Angle ( )
-5
Back of Bar to Cutting Edge (Decimal Inch)
1.2500
Back of Bar to Cutting Edge (mm)
31.75
Head Length (mm)
22.23
Head Length (Decimal Inch)
0.8800
Insert Inscribed Circle (mm)
15.88
Insert Inscribed Circle (Inch)
5/8
Insert Inscribed Circle (Decimal Inch)
0.6250
Complete Insert Compatibility
NP.. 51R