Holt M-35... '24 or '25?

Hello,
My M35 engine S/N is 80017, and there is no other brass tag with tractor serial # on it...

It has eisman (spelling?) magneto & a zenith carb.

From Dr. Lorry Dunning's research in back issue ACMOC 54, I take this to make it a wausheka engine produced in Peoria in 1924?

Since Dr. D's research includes the sentence about (caterpillar's records saying Col. Babcock's letter stated engine S/N 80001 would be paired with tractor S/N 70001 in 1925), would I likely say my dozer is a 1924, or a 1925, (or a 24/25?!)

Really want to make sure I understand it's year, before I determine if parts on it are correct to the year it is....it has wavy caterpillar across the radiator, raised HOLT beside radiator, and across top (side) of engine.

I feel the present operator's seat on it is something newer someone added because they had one handy and it was being used... would like to determine what year the dozer is, as I'm hoping to replace it with the "curved back bucket seat?" and don't want to make an expensive mistake or worse, take off something that could've been original. (I don't know what proper term for the curved back seat is... it's the one pictured on "SWISHY"'s two-ton caterpillar website picture.)

It seems confusing as it seems to be right on the transition of Holt & Best combining to become Caterpillar if I'm understanding correctly...
I inherited it from my dad... he also had additional loose parts "top of radiator wavy caterpillar" part, AND a pair of the cut-out HOLT sides of radiator … I don't know if they came with or off his dozer...
Thanks for any input!

Hi I hope you can get this issue sorted. Do you have any pics? This will help people a little.
I have a 1926 and mine has a eismann magneto and zenith carb.

[attachment=50813]pan seat on back of 1924 Holt.jpg[/attachment]

Thanks for your reply Blakeystew! Struggled some w/ posting pics ... Grrrr… no one in our house under 50 with better computer skills! LOL
Haven't figured best way to post...figured if I put a reply or ? on ten year old thread, they won't be seen...

I keep hoping maybe my dad had the tag with the tractor serial# fall off & I will find it somewhere...but I doubt it

I've read where other people have questioned since the holt engines began # 80,000 in Peoria, and the tractors began #70,000, were they put together in one-to-one correspondence? (Even if they were , I guess I still can't know for sure that my engine SN #80017 couldn't have been put in a newer or older tractor at some point, right?)At some later point if I wanted to sell wouldn't want beat up if tractor wasn't same year as engine. Being engine M35 #80017 I feel it has to have been made early 1924 prior to a dynamotor test letter on engine #80118 was sent in Holt Company August of 1924.

The mention of Caterpillar records (August 1925?) sounds like Col Babcock said the engines (80,000's) and tractors (70,000's) would be paired w/ one to one correspondence... but would that mean going BACK to those engines & tractors like mine that should've been the 17th engine made in Peoria 1924, and then adding the tractor #? (I would assume my engine and it's tractor were sold and gone before the merger which I've found mentions of happening April/May of 1925?)

My Dad purchased Holt years ago from a man ill w/ cancer who passed away within a year or so of that... I've seen the handwritten bill of sale... if I can find it I may try to figure if there is any remaining family who would know any tractor history.

If the tractor is same 1924 as my engine #80,017, it should have the curved back military type of seat, (not the newer pan seat "on a leaf spring?" that is on it.) Part of my concern with it's present seat is that being backless it might be part of why my Dad fell off it once, & crawler was stopped by some bushes! He'd driven it before w/ no incidents, but if they have a tendency to "lurch", thought seat w/ back might help stay with it...it needs to be driven but...

Hoping anyone with these early crawlers will correct me on anything...

Thanks!