When you get the replacement, note that the vertical take off pipe can stick almost straight up, or be angled back. It's not critical, but just worth knowing.
My original pump when I replaced it during the rebuild, was working fine. The replacement had that pipe at a different angle, and whereas on the old one, the impellor was large and a tight fit in the housing, the replacement had a smaller impellor which had a much bigger clearance. It still worked OK though. I kept that original pump for years intending to have it reconditioned, but unless its still in the loft, I must have thrown it out. That was 1990.
