Testing a scope well enough to order the matching Chromacor sight-unseen requires a considerable amount of knowledge and skill, not to mention time. Hence, Astrobuffet recommends that anyone not already owning the achromatic scope they desire a Chromacor for, should consider buying a matched set.
$1349 New 150mm f/8 Celestron OTA/rings/caps, matching Chromacor/accessories
$TBA New 120mm f/8.3 Celestron OTA/rings/caps, matching Chromacor/accessories
$POR laser collimation, adjustment (focuser, objective, your diagonal, etc.), machining services, custom rings, etc.
Pictured below is my outdoor real-sky test setup for mounting, testing, and matching Chromacors to up to (6) 120mm or 150mm Celestron refractors at a time. The mount is an Astro-Physics 1200 QMD, with A-P 24" ribbled plate (hidden) holding a 24" x 48" sheet of plywood. With the four 150mm scopes shown, it required using four of my five18# counterweights on the standard shaft. For six scopes, the special A-P long counterweight shaft is used.
I plan to move to using an indoor all-weather test setup after sufficient practice and calibration using real stars. I'm definitely ready for indoor testing after carrying the pier and mount head out by hand in one piece, assembling the weights and scopes onto it in my driveway, and then lugging the whole assembly on a handtruck to put it away while half-frozen! I think that only adrenalin, and maybe the small percentage of muscle still left from rowing on the River Charles a long time ago, saved my life after I tipped the handtruck back a bit more than planned. ;-) Ah yes, an indoor optical test bench sounds better than the astro version of Fear Factor.
On the right, that's my first personal Chinese refractor, a 120mm f/8.3 Skywatcher purchased at Astrofest 2000 (along with a sibling 150mm f/8 Skywatcher) before I got into the business. It's mounted on a Takahashi EM-10 which I took to Australia in 1999 for the grazing Mercury transit. The perfect A-P Traveler which I took to that event and still own, cannot keep up visually with the 120/Chromacor combination on Jupiter, but of course is preferable for astrophotography. It had better be, seeing as I paid $1000 over list price for that Traveler! The 120mm Skywatcher with Chromacor is soon headed to a famous scope reviewer, to test out on his own EM-10.
Don't ask me if the Celestron, Skywatcher, Bresser, Hoon, Synta, and other scopes are identical or not, optically. I can only tell you that the 150mm Skywatcher and Celestron optical tube assemblies are physically different. Beyond that, it's anybody's guess. I've heard that even some of the brands themselves aren't sure if other brands are identical or not. Welcome to the global economy!