I've done the same thing ... but, thankfully, just once. Battery went flat, and I'm running a transitorized ignition module instead of points. I called FS Ignitions and they said it should be fine, just charge the battery and go for it...so, I did. Started fine, ran fine...still does.
Now...my shut down procedure calls for me to turn off the fuel as I pull into the garage....then fully retard the spark...close the GAV finger tight...wait for the carb to run dry. Then, raise the gas lever to fully off...and turn off the switch. I remove the key and MAFCA key ring and hang the ring over the gas lever where it stays till we're ready to go for another drive. If I look into the car...I better see the key hangin' over the gas lever...or I know I probably left the switch on again.
So far...it's worked fine for me. I keep our car in our locked garage, and it's blocked in by my wife's Honda on the drive way...plus, I live in a gated community where there is no access to public streets, etc. I wouldn't recommend my little ritual to just anyone, but it's worked for me since I inadvertantly left the switch on that one time.