Key won't turn in the ignition, Need help Options

[Thunderchief]

The key was being difficult going into the ignition so I sprayed a little wd40 into it yesterday. The key went in a lot easier today but now it won't turn. Ideas would be appreciated. Thanks.

[dangrouche]

I had similar problem in my 1974 that the key would sometimes snag and I was unable to turn the key at all. Your assembly will look like this (not the one with the red tape. Don't try to remove that pin underneath that red tape, don't ask (IMG:style_emoticons/default/confused24.gif) you see the pic with the red tape. in the upper right of the pic, you will depress the hole with a pin punch 1. the key should be in the tumbler assembly
2. depress with a pin punch into that hole
3. while the punch is applying pressure into the hole beside 150A, this releases the tumbler assembly, then you pull out the key and tumbler assembly as a unit.
4. taking the actual tumbler with the key wafers is tedious and I had to build a wooden jig to support the assembly while gingerly tapping the roll pin to then get the thing apart.
you use a punch to drive out the roll pin, where I wrote the word "FAT" on the keyway assembly. once you get the tumbler out, you clean the wafers individually and the "tumbler carrier" as you see in the last two pics

I thought my key assembly was toast before commencing this project (took about 2 hours), but purely cleaning out brass debris from 45 years of use, made the key work perfectly butter smooth. I believe the "Cabinetmaker" member on this forum repairs these things for a fee. He did give me some advice which prodded me to disassemble the thing. I've searched this board and never found anything on how to disassemble the tumbler assembly.