If you remove the shifter do not, repeat, do not get rid of it. In fact if you do remove it send it to me. I'll give it a very good home. I have to agree with Joe. That is a classic piece of iron that you might want to think twice about doing any alterations to; especially if it means cutting or welding. I'd store that thing and let it build in value and choose another bike for motorizing. But that's just me. There are a lot of guys doing the later version of the stingray, the occ choppers are very popular but if it was up to me I'd take very good care of that 69 and be glad you have it.
Tom