Rule 1, take your time. You are going to fix this, it will work again and every bit as good as when you were happy with it, but you will start by accepting this can not be rushed. Don't like to be dictotorial, but the seemingly longer systematic, methodical route is often the quickest. Probably you did short something live to the chasis, which you may or may not have grounded. If it wasn't grounded then you may have shorted two or more nodes together. If the unit hasn't worked since you shorted it you have done something irreversible - like blow a tranny or IC. If it works out the box then all is readily recoverable. The wee poly bag is unlikely to have blown anything as most ICs (since the 70's) have protection diodes on the inputs/ outputs. Germanium trannys are easily blown I'm told. No personal experience though. If you used tranny/ IC sockets and have spares you could try fault finding by substitution, ie plug in spares, does it go? type idea. The other thing about the poly bag insulator is that if your solder joints have sharp ends to them, they'd have little difficulty penetrating the bag and making their way to the chassis again. Trimming off the tops of the solder joints may have opened a node, or shorted two together. For a few bux you can buy a x9 magnifying glass. Give the board a squint through it. Key question is, does the assembly still work out of the box?