[TowerTalk] Cushcraft 30/40m kit for W3S work on ATB34?

[G.P. Widin]

A friend has an update kit for the Cushcraft A3S for 40/30m, that he's willing to sell.  My old AES catalog says this is an A-743. 

My tribander is a Cushcraft ATB34, the predecessor of the current A4S Cushcraft beam.   I'm interested in adding the 30/40m kit to my older tribander, but I don't know if it's truly compatible, despite the apparent very high similarity between the two series of antenna.  Also, his kit is for the A3S the "3-element" yagi, while I have the (so-called) 4-element version in the ATB34.

With that background, I have a few questions--
--Does anyone know whether the update kit for an A3S will work on the ATB34?
--Does anyone have the instruction sheet for the 40m update kit for the ATB34, assuming that there was one?
--Is there anything inadvisable about trying to add a 30/40m update to the ATB34?  

Of course, I could set up instead to load the boom on 40m, as suggested by N4KG some years ago, but of course that involves some experimentation...  On the other hand, maybe the experimentation to do that would be no worse than that to adapt a "3-element" update kit to a "4-element" beam from the older series.

Answers and comments, please?
--
73,
  Greg, K0GW
  Reply to k0gw AT arrl DOT net