OA 40-48 mechanical access

Also, never hesitate to request photos on boats you have an interest in, even specify the shots you want. That will at least provide you with enough to know whether further inspection is worthwhile.

Just don't assume that there's a consistency across models or sizes or years.

Hawgwash, I'd be curious where you found the data. There seems to be a dearth of configuration data on OA production. Does SOLDBOATS have engine data(maybe that would be more reliable than the sales price "data")?
I'm currently considering a 440 SD that has twin TAMD61As and wondered if they were original.

Well, what are the hours on the engines and what are the hours on the generator. If they make sense, they're probably origional engines. Usually the generator has 1.5-2x the amount of hours the engine does on most yachts that size.

That is a helpful guide, Captain J. My question was referring to OP's list of which engines were installed at time of Mfg.

Seeing my posting [12/24/2016 07:15], I think a clarification is in order. I was using the OP's display name as an appellation, not taking exception with their veracity.

It had occurred to me last night that I had not tried direct contact to OA. I must be too accustomed to buying makes who's manufacturer are out of business. Thanks for the contact information.

One or two comments on DD 8.2s. While it is convenient to dismiss these out of hand and parrot the automotive press, late model 8.2s that had all the updates and modifications are in fact reliable and are truly fuel misers. Yes - there are a lot of hoses and I'd recommend replacing them with silicon-based hoses, but later model 8.2s that have had normal periodic servicing should provide a long life in marine service.