I don't think I'd ever heard about the axial focusers being swapped out for the later focuser. I simply assumed that Celestron used up the castings they had on hand by making the adapter mine has for the later visual back. I never did make a connection with KBEW, unfortunately. It might be fun to try, though.
I have been able to validate another scope like yours by photo from a registry post by CCD-Freak, #195. Since I've not [yet] found any in the serial number range below Tinky, I'm beginning to doubt the "conversion" story, although it was from a highly credible source known to me personally. If this did happen, it was a rarity since we do not know of any below #135, and no Axials above have turned up.
As I recall the conversation, the individual must have had an Axial model at one point, because he recounted how clumsy and upsetting to photography the mechanism was compared to the later focuser.
I'm going to continue reviewing photos in registry entry posts - in hopes of identifying the point where rear cells transitioned from needing an adapter, to being natively machined for non-Axial focus, and again when the casting changed to no longer being capable of accepting the Axial machining.
From registry entries we have learned of the following distinct evolutionary stages of Early (aka Sand Cast) C8s:
- Axial Focus Tricolor OTA 422mm, provisions for main mirror collimation (3 screw holes in the rear cell), no base tag, SN on Focuser
- Axial Focus Tricolor OTA 422mm, no base tag, SN on Focuser
- Axial Focus Tricolor OTA 422mm, SN on base tag
- Adapted STD Focus Tricolor OTA 422mm
- STD Focus Tricolor OTA 422mm long
- STD Focus OTA 396mm long
- The 422mm long OTA cannot swing fully down between the forks with a spun aluminum cover in place.
- This rear cell casting appears to have been lengthened so the SCT thread "mound" replicates the position of the missing Axial focus mechanism, or the later "Adapter".
- The end of the Tricolor era may be marked by the shorter 396mm OTA, commonly supplied with the Spun cover.
- The end of the Sand Cast era is marked by different forks and a new RA base with 3-prong power in the bottom
There could be further in-between stages as well. Once a photographic basis for a timeline is established, this evolution will be depicted better in the registry.
Thank you all again, for participating
P.S. tim53 - I have been trying to work the KBEW angle for some time. Will advise should anything else turn up.