Worksman frame questions

[Ldog33]

Just received a worksman frame that I will start building up so I have a few questions..
First off, what is the widest rim/tire that will fit? Would love to get a set of the copper colored rims (26) that our host is selling?
Can I install a monark springer, I'm guessing yes?
What is the seat post size so I can have a heavy duty one bent, does not appear to be a 1 inch, maybe 22mm?
Thanks

 

[old_skool]

not sure on the max rim/tire width, but the seatpost is 7/8" I think

 

[Wildcat]

The copper 57mm wheelset will fit with 2.125 tires. My Worksman has those size tires on it, the chainstays are the narrowest part, but there's still plenty of room.