While this is almost 6 years later than your request, I do have a service manual for the 6150 in addition to the owners manual. Spare parts, I do not have. I purchased one in around 1969 and still have it. While it does not get much use now, it does get used ocassionally . Remarkably it still works. I will gladly copy each of the manuals and send to you - or, if time permits, I will scan them in and provide them in a (non-searchable) pdf format. Just provide contact info.
I hope this helps - Retiree