This is the Heathkit solid state grid dip meter model HD-1250. Sold with the manual and case to hold the meter and coils. It uses a standard 9v battery.
Unit from estate is sold but Dave (N2VUZ) has an identical / working one FS.
Here’s a YouTube video showing how to use the dip meter as either a signal injection meter (standard use) or as an absorptive wave meter; https://www.youtube.com/watch?v=_HwIL6mqq_k