have read an earlier posted fault :
l have a1968 1000 went to take it for mot yesterday - but had to use for the first time my starting handle

luckily passed with flying colours and no advisories - but garage said it was not a flat battery - because by pressing the red button on the solenoid she started - it was the ignition switch - purchased one today and fitted new one but same fault - will start on the red button but not the key ! tried it dozens of times and it worked twice - so took a wire from the ignition switch to the small terminal on the solenoid and hey presto first time - but not another

so have given up till tomorrow have an appointment tonight - but would really appreciate some help "please" have read one about a wire from battery to small terminal on solenoid - am positive earth so presume its the one to use ?
Thanks
ps have checked starter lead for tightness