When I looked up a key switch for a 102 it gave me results about a 2 position switch, Wasn't sure it was correct though. I don't own a machine from that series but I'm pretty sure they all should have the three-position switch. Off, On, and Start. Start is spring-loaded so that when you let go of it it pops back to the run position.
I would recommend simply replacing your starter switch with the correct one
I just noticed your comment about driving it down the street to bring it home, I love taking my cubs all around the neighborhood whenever I can
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'70 107 with k301 engine swap
'71 106 with 38" deck
'70 147
R with factory replacement k321, 42" deck
'61 Original with 38" timed deck
'63 70 "pinkie"
1863 with 54" deck
'46 Farmall H, '50 Farmall Cub
105 x2 (parts)