I think I am in the final innings of a now 8 year restoration of a 1935 845 which is nearly the same car as 1934 840. I’m afraid I will have very few useable parts after the dust settles but lots of pictures and some experience. Many on the message board have much more Pierce experience and can help. David C. has been a big help to me. Parts and funds to buy them will be a major problem of course, significantly more challenging and expensive than ’50’s Packards.
No shop manuals, but one of the greatest assets of the PAS is 50 years of Service Bullitens that are now key word searchable and downloadable on the website.
The ’34-35 parts manual is sometimes useful and worthwhile but limited utility for interchange.