I'm currently putting new seal and gaskets in a np435/205. Think about putting in a np205 twin stick conversion. The question is, do you have grind the shift rail?

 

Yes but it is difficult to get it right. Someone sells a kit with the pin already ground out. Try a search, but as I remember they were around $100. I ended up just pitching the interlocking pins in mine, after the grinding didn't work.