I feel guilty having you run up phone charges on my account, but my phone number is (315) 783-4078.

I see your point about the inappropriateness of the 1800 pump.
My service manual says that the 880 Roosa used a .29 dia. plunger and the 770 used a .27 dia plunger.  I don't know what the 1800 used.
The best option would of course be either of those, but I think they were relatively rare.
Now I do have a line on a couple of different used AMBAC pumps, and a shop in Syracuse has a NOS AMBAC head for a 'BUDA' application, but it might have a 7.5mm plunger, instead of the 7.0 used on the Olivers.  If it is one for a WD45D, and I turn it down, you can bet I will post the information on the Allis board.

As a side note, I sent an email to AMBAC telling them that they ought to consider a production run of plungers.  They actually responded:

&quot;Yes, we would be interested in providing parts we can make money on. If
you believe, there is a market for hydraulic heads please advise what
part numbers and quantities you are interested in purchasing. To
remanufacture these heads we need to manufacture blank plungers, which
will be fit into the hydraulic head. Please go to our web site at
<!-- w --><a class="postlink" href="http://www.ambac.net">www.ambac.net</a><!-- w --> and click on technical data sheet and scroll to the bottom
of the page. Here you will find the information on your hydraulic head
and other. Please advise the information requested.

Best Regards,

Kenneth W. Smith
Marketing Manager 
Ambac International
910 Spears Creek Court
Elgin, SC 29045
800-628-6894 (Toll Free)
803 462 9625 (direct line)
Fax: 800-542-8230 Domestic
        803-735-2280 International
E-mail  <!-- e --><a href="mailto:ksmith@ambac.net">ksmith@ambac.net</a><!-- e -->&quot;

There were at least two different Heads used that I can find; one is the HD3690A and the other is the HD4745A; I think the delivery valve is different, the later head would probably retrofit the older pumps.  I am sure the plunger is the same.
The only way this would happen is if some nationwide co-operative effort pushed for a run of (for example) 200 plungers.  Do you think this would satisfy current and future demands?  Perhaps the HPOCA could run with this.  Or is this a dead horse.

I have not responded as yet....

Larry Wollum
(315) 783-4078