The article to repair the TI30 is one of the the most read articles in my blog.
Here is an article , not especially for the HP67 repair in german,. Therefore there is a cut out of HP67 repair procedure for people that can’t buy the special tube mentioned here. Please read the translation:
After I could not find this said pink fuel tubing for the friction wheel I have used a piece of an approx. 3 mm thick rubber plate of tyre quality and grinded it round in a drilling machine until the diameter was 6.4 mm. Works great!