Hi beachhouse.
Time for you to start the starter search yourself.
The first thing you will need is the Yanmar part number.
Not just that it fits a YSM 8.

Once you have that number start searching for the Hitachi equivalent part number.
Then once you have the Hitachi number start looking for what make and models car it was fitted to.
Once you have that information, head down to your local Japanese car wreckers and Bob's your uncle.
From what I have hear Isuzus are the match but can't vouch for the year or model.

Here is an English site with information on YSE/ YSB starter motors. You will see cross reference numbers here.
These will be Chinese manufacture but don't be put off by that.
By all accounts they are reliable and for the low prices a bargain.
www.startermotor-alternator-store.co.uk/yanmar-ysbyse--1kw-marine-starter-motor-s2185-4470-p.asp


Good luck.

gary

A guy I know worked for Volvo a long time ago. He found out all the most popular starter motors and bought a container load. He just changed starters motors in the end. Left his job and started his own company.
So as Gary said track down the part number and buy one. Sometimes you can peel of a sticker and the brand and part number are there. Mostly they are painted over.
Did you spray it with WD40 and hit it with a hammer!!

EBay has starters, brushes, brush holder and more
www.ebay.com.au/itm/124225940997?_trkparms=ispr%3D1&hash=item1cec716e05:g:dx4AAOSwkJ1e6d4S&amdata=enc%3AAQAGAAACoPYe5NmHp%252B2JMhMi7yxGiTJkPrKr5t53CooMSQt2orsSxXDXcCydCuSj2Tq2S%252F3GngIgc3P6H36lhlbyZD7%252FrorrW9hd%252BIHDLaTbvkJ7jbYZS8hzuQFufLxhEsBPIt3h3eEkiK6ewMt4UCofulrzl%252BaKxMUrU9t43wx9%252FHYEfA7w2%252FkMBztolXg5c9JqG%252FwAARbuRhrh2aUqpc91c5njajNDP%252BC%252F3JjREeHk9ShAxKUZHh6l0H%252F1USRsX8OiEJD7yN9CqXGRXCv5rKa6Db29mLl%252Bu%252FWAOXu5ugH1gP1L2VQbPVWaTPMAI7XId0FJkyAQEGeStkPx4jatBDl%252BkAdmz49TYW1mcwwNcnZJ%252FJvIJCn35gZowQIrc47MkjxkeGgr7FZOnmFIwi5KZPrSMKV4i88qkzlM6lzHx8gzBGobm5QagJvh7k%252FuNljTHRJouKSfwHcfF6%252BPG%252BNZ4cMeEgRcRDwzM%252BZekKUv2gcqxRHa7PypjRnsSnRjjj783wLbbYgKY%252FQDLEBvRleY5e0pLfD5vy%252Fgcyma0WKH2i%252FkM7X6EvtPkjpSMxKoOtUaIN7TIZ2AInNAvCGBg3hNPHRXcR%252Big175kjU%252ByAUj3hDxDe4DPAuKelFxbaXqv5Gr4ykyW%252FEP4VP1jyrxOfJXTuFSCit7FbySEv3ucth3%252BU9nLQ2DdekAfw5QUciWLdw%252F6QZbId6OE3eZEvB3PsoMW0U7cbMbtBS4SlGGFZIATJESA0eOZElilb8fPn6nxhKFa%252Fflr5j2A9HGD018KOabfj2EtcZWqeya%252BVpuFWKoMOLpzcMm2hk0qr7of5ZEoLbylMycCjbSNC6Lx6CdXeVk8Fc6v53QByyCwYQLRr2plE%252Fd7jA%252FMjkbkYw4SoHuV4WlMk1zWC%252By4A%253D%253D%7Cclp%3A2334524%7Ctkp%3ABFBM1KzakKBf

The old skill of rewinding electric motors is still around. There's a mob out Cannington way near the railway station that do small motor rewinds. A mate of mine had a small unusual conveyor motor rewound recently.

It might be worth giving the Wooden Boarshop in Sorrento, vic a call. They had some parts for my old PMX 6