After some false starts, finally managed to have Basilisk II 64-bit and Mac OS 7.5.3 working on macOS Mojave V10.14.4 on a Late 2012 Mac mini. Beauty!
The classic screen takes me back to the 90's with a sense of deja vu and a bit of revival of PTSD suffered therein (a different and very long story).
Also have working following old Macs
- Power Mac G3 (CD/FDD)+ External SCSI Traxdata CDR4120 Pro CD Writer
- PowerPC Mac Performa 5400 (CD/FDD)
- External SCSI FDHD (might need a clean/service to be functional)
- External SCSI HDDs, a few, hopefully still working
- External USB FDHD
- External USB DVD Writer/Reader
- Mac PowerBook 180C (was working 20 years ago but battery leaked/failed, going to try building another battery and service the laptop to see if can live again.
- Also have two Mac IIci in dubious condition. To be revived.
Now need to learn how to
1- Transfer my old Mac applications and documents on 400k, 700k and 1.4k floppies and HDDs by reading them on above Macs, creating disk images, etc and burning to CD.
2- Copy info from CD in Mac Mini to Shared folder in Basilisk and installing old apps to read them.
3- Transfer information to use under modern apps (don't have yet) in Mojave V10.14.4 and later.
Any assistance would be most welcome. Thank you

The good news is that each of those devices shares a transfer method with one further up-stream, so you should be able to transfer data.

The external SCSI HDD should work with all the SCSI devices, assuming it is terminated correctly and you have the correct cable. Once you get to the Performa, you should be able to transfer via AppleTalk over IP (over Ethernet) to/from all the more modern machines. So this will likely be your crossover machine. Useful that it can read 800k and 1.4MB floppies as well. You'll want to use Disk Copy 4.2 to create your disk images to ensure all data gets recorded. These images should be readable by Basilisk II and Mini vMac, as well as by SheepShaver. They won't be mountable in Mojave, which doesn't natively support NDIF (the container type) or HFS (the filesystem inside).