I think the electronic ignition the other person (sorry forgot who said it now!
) may have been on of the "new breed" of contactless (rather than contact-assisted as the Elektor home-build one was [i have vague memories of it] and most other "bolt on" aftermarket electronic ignition units of the time such as the Sparkrite SX1000, SX2000 etc units that literally clipped onto the coil with plastic coated Terry clips and had a DPDT- centre off changeover switch for contact-assisted or just contacts for the ignition.
The downfall of the contact-assisted units was that over time, the contacts could "glaze" themselves as there wasn't enough current flowing through them to burn off oil residues from slightly fumy engines. This could cause misfiring and the answer was to temporarily revert to contacts only to clean them up - usually just a few days use.
https://123ignition.com/products/?filter_brand=volvo
Something like that where the distributor is rebuilt with an electronic (Hall Effect i think) trigger in it, the ballast resistor is bypassed and the coil i believe is replaced too to make it a bespoke complete electronic system is what i think was being suggested.
There are similar variations on a theme where a small module fits in place of the contact breakers and drives the coil directly, no other mods as far as i know.
These days a contact-assisted add-on unit would probably use a MOSFET instead of the venerable 2N3055 to reduce the switching voltage across the semiconductor and also provide faster switching.