I am not talking about distortion over time, rather than manufacturing variation which may be over time.
If it is any help, I own three Waterman 52 1/2v, one BHR, one gold (0552) and one silver (452), and can tell you that none of the caps is interchangeable. The three pens are different lengths, albeit slight for the metal pair. Whether all BHR are the same length, I do not know. Given my gold and silver are different from each other let alone from the BHR, good luck.
To spell out the comment I have bolded above, these are various measurements of the three 52 1/2V pens I have. The three numbers on each line are for the BHR, the 0552 and the 452 respectively:
- Capped length (excluding ring at end): BHR 109 mm, 0552 88mm, 452 92 mm
- Uncapped, nib tip to barrel end excluding ring: 102 mm, 86 mm, 88 mm
Note the differences implied for nib-tip-to-cap-end clearances in the above.
- Cap length: 54 mm, 46 mm, 47 mm
- Section length excluding threading: 14.3 mm, 12.9 mm, 12.9 mm
- Threaded length: 6.3 mm, 7.5 mm (only ~5.5 mm of this appears used), 5.6 mm
Figures without a decimal are rounded to the nearest millimetre, otherwise 100 µm. Measuring the threads next to the section, or just inside the lip of the cap, it appears the BHR cap is about 100 - 200 µm smaller than the gold-filled and silver caps.
The main caveat I have offered on my information is that, although all 52 1/2V pens, these are three variations in more than their finish. The measurements show this, and on attempting interchange the BHR is incompatible either way, while interchanging the gold and silver is a slight but obvious kludge. Without multiple pens of one exact type, I do not know whether there might be variations over time within exact types.
Afterthought: Consider holding a 90 mm pen, and you can see why I post those.
edit: clarify opening line
Edited by praxim, 16 November 2017 - 01:19.
Anyone owning three or more working pens is in no position to disparage choices by others.