I can't quite be certain as it's hard for me to tell from the photos if that insert is a screw-down positive rake or a double-sided negative rake. I lean toward is being the former, which would have a countersunk hole. If it also has 11º clearance angles on the sides, then it's a TPGT or TPMT 321 or 320.5. That one does appear to be ground on all sides, and if so it's the TPGT.
Those are getting harder to find. The more common thickness is 3/32"- 2.5mm for a TPGT32.51 or TPGT32.50.5. The angle is hard to judge in photos. If it's 7º it's a TCGT 321, and if it's 5º then it's an oddball TBGH 321 from Circle and that's the only maker you'll get them from.
You might be able to use the slightly thinner TCGT32.5x size, depending upon what holder or boring bar those are used in.
Those are getting harder to find. The more common thickness is 3/32"- 2.5mm for a TPGT32.51 or TPGT32.50.5. The angle is hard to judge in photos. If it's 7º it's a TCGT 321, and if it's 5º then it's an oddball TBGH 321 from Circle and that's the only maker you'll get them from.
You might be able to use the slightly thinner TCGT32.5x size, depending upon what holder or boring bar those are used in.