No. 730 was introduced to allow slitting and bevelling of soft insulating board by the use of thin razor blade type cutters. Two cutters positions are provided. A vertical position for slitting and 45° angled position for bevelling. An attachable fence was provided for bevelling work. It remained in production for about 15 years. This example is boxed (although it’s past its best) with 4 blades and is in good condition.
If you are wondering about the plane knob, it was in the box and my son didn’t realise it wasn’t part of the plane however it will be sent as pictured.