I am looking at a 1970 AT1, but it really needs fork tubes (part # 248-23124-00-00). I see none on eBay new, and the used ones are, well, used, if you catch my drift.

I know there are a lot of members with these smaller models. AT1 and CT1 used the same part #. Someone must have had to do this before me. Is there a source for new tubes? Franks?? How about re-chroming? Is the "bushing" at the bottom of the tube an issue for the chromer? Would that need to be removed for them to do the job?

Right now the condition of the tubes is such that it would be a deal breaker.

Appreciate any info! 

Hi Steve
Check the DC Plastics website, they sell a brand called Dachi and carry several sizes, I am not sure if they have what you need, I’ve never bought from them, but there are a lot of positive reviews of them on this forum. I also think some other models and years will work if you swap the complete fork assembly including the brake backing plate, there is a thread on that subject somewhere on this site.

A good source, and thanks for the reminder. They do have tubes for later models, as well as the DT/RT series (currently all sold out  ). Frank's does not carry (as a standard item, anyway), but I have sent them a quote request. Maybe they can make up a set., but dealing with that bushing at the bottom may make things awkward. So no luck for this earlier year that I am interested in, as far as "new". 
So, I am looking at re-chromers. There are some in the UK, as well as Australia, but I found these guys in Santa Fe Springs Cal. 

www.ecgrinding.com/motorcycle-fork-repair.html

Anybody ever deal with them? Members in Cal?

I think Dave Kolbo ( KDI )  used them on some of my show bike projects.
You may have to give him a call.

Tell him I sent you !

Another option, I use to work in the heavy industrial equipment business, we worked with a lot of hydraulic cylinders for heavy equipment, many of the hydraulic shops were equipped to turn down & re-chrome the hydraulic rams, would be the same procedure for pitted fork tubes. Try calling a local hydraulic cylinder repair shop or Caterpillar, John Deere, Case dealership near you. 

I recently bought a set of Diachi tubes for my DT1 from DC plastics and they were terrific

I am/was in same situation with my 1970 CT1-175 For some esoteric reason, the steel lower end forks chrome tubes are not avail new so I also contacted the place in Sante Fe Springs. They are a hydraulic cylinder place but also have a motorcycle fork tube department. That said, I decided the cost of brand new Dachi tubes and some used, later, ebay forks was a better path.
Regards,
Joe