How can you ID an original H&M block?

[SanDogDewey]

1969 Donzi 16 Ski Sporter. Didn't see a tag on the bell housing. One exhaust manifold has been replaced.

http://i983.photobucket.com/albums/ae319/SanDogDewey/Donzi/DSC_5235.jpg

http://i983.photobucket.com/albums/ae319/SanDogDewey/Donzi/DSC_5241.jpg

http://i983.photobucket.com/albums/ae319/SanDogDewey/Donzi/DSC_5229.jpg

http://i983.photobucket.com/albums/ae319/SanDogDewey/Donzi/DSC_5218.jpg

http://i983.photobucket.com/albums/ae319/SanDogDewey/Donzi/DSC_5217.jpg

http://i983.photobucket.com/albums/ae319/SanDogDewey/Donzi/DSC_5216.jpg

http://i983.photobucket.com/albums/ae319/SanDogDewey/Donzi/DSC_5209.jpg