A lot of companies are advertising EICRs for under £100. I don't know, but I'll bet that is for a small 1-bed flat, and the price would be higher for yours.
Quite honestly, I don't know how they can do it for that price.
Mid-sixties with a re-wireable "Wylex" consumer unit suggests you have the original wiring and installation.
Same procedure as for a newer house, but I personally would take a little more time over it than normal.
Be prepared for the report to identify a whole load of concerns, mostly regarding bringing the system up to modern standards.
I would say it takes around 3 hours for the inspection, plus more time at home completing the report with all the various suggestions and concerns.
Allow around £150.
Installation of EV charging is not likely to be a problem.
Apart from a new Consumer Unit, there may be a necessity to upgrade the Earthing arrangements. The Report should mention that possibility.